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Sample records for metal-organic framework material

  1. Purification of metal-organic framework materials

    DOEpatents

    Farha, Omar K.; Hupp, Joseph T.

    2015-06-30

    A method of purification of a solid mixture of a metal-organic framework (MOF) material and an unwanted second material by disposing the solid mixture in a liquid separation medium having a density that lies between those of the wanted MOF material and the unwanted material, whereby the solid mixture separates by density differences into a fraction of wanted MOF material and another fraction of unwanted material.

  2. Purification of metal-organic framework materials

    SciTech Connect

    Farha, Omar K.; Hupp, Joseph T.

    2012-12-04

    A method of purification of a solid mixture of a metal-organic framework (MOF) material and an unwanted second material by disposing the solid mixture in a liquid separation medium having a density that lies between those of the wanted MOF material and the unwanted material, whereby the solid mixture separates by density differences into a fraction of wanted MOF material and another fraction of unwanted material.

  3. Emerging Multifunctional Metal-Organic Framework Materials.

    PubMed

    Li, Bin; Wen, Hui-Min; Cui, Yuanjing; Zhou, Wei; Qian, Guodong; Chen, Banglin

    2016-10-01

    Metal-organic frameworks (MOFs), also known as coordination polymers, represent an interesting type of solid crystalline materials that can be straightforwardly self-assembled through the coordination of metal ions/clusters with organic linkers. Owing to the modular nature and mild conditions of MOF synthesis, the porosities of MOF materials can be systematically tuned by judicious selection of molecular building blocks, and a variety of functional sites/groups can be introduced into metal ions/clusters, organic linkers, or pore spaces through pre-designing or post-synthetic approaches. These unique advantages enable MOFs to be used as a highly versatile and tunable platform for exploring multifunctional MOF materials. Here, the bright potential of MOF materials as emerging multifunctional materials is highlighted in some of the most important applications for gas storage and separation, optical, electric and magnetic materials, chemical sensing, catalysis, and biomedicine.

  4. Lanthanide Metal-Organic Framework Materials

    NASA Astrophysics Data System (ADS)

    Hsieh, Ping-Yen; Green, Mark A.; Briber, Robert M.

    2009-03-01

    A series of lanthanide metal-organic framework materials (MOF) with variable organic linkages including benzene-dicarboxylic acid (BDC); 1,3,5-benzene-tricarboxylic acid (BTC); and 1,3,5-tris(4-carboxyphenyl)benzene (BTB) have been synthesized. The low density and high porosity of MOFs make them candidates molecular sieve or hydrogen storage materials. The crystal structures have been determined using a combination of single crystal X-ray diffractometer and synchrotron powder X-ray diffraction work. Holmium with the BDC ligand material (Ho-BDC) crystallizes in a monoclinic C2/c space group, with lattice parameters of a = 17.06 å, b = 10.67 å, c = 10.57 å, b = 96.12^o. The crystal structure of Ho-BTC is in tetragonal P 41 2 2 space group and Ho-BTB is in a triclinic P-1 space group. A comprehensive examination of Ho-MOF with different ligands by x-ray and thermogravimetric analysis shows that there is a stable nanoporous structure for dehydrated Ho-BTC up to 250^oC. The same phenomenon is not observed in the Ho-BDC and Ho-BTB materials. The collapsed structure with BDC and BTB indicates the stability of dehydrated samples is strongly related to the interactions between the metal and the organic linkers.

  5. Metal-organic framework materials with ultrahigh surface areas

    DOEpatents

    Farha, Omar K.; Hupp, Joseph T.; Wilmer, Christopher E.; Eryazici, Ibrahim; Snurr, Randall Q.; Gomez-Gualdron, Diego A.; Borah, Bhaskarjyoti

    2015-12-22

    A metal organic framework (MOF) material including a Brunauer-Emmett-Teller (BET) surface area greater than 7,010 m.sup.2/g. Also a metal organic framework (MOF) material including hexa-carboxylated linkers including alkyne bond. Also a metal organic framework (MOF) material including three types of cuboctahedron cages fused to provide continuous channels. Also a method of making a metal organic framework (MOF) material including saponifying hexaester precursors having alkyne bonds to form a plurality of hexa-carboxylated linkers including alkyne bonds and performing a solvothermal reaction with the plurality of hexa-carboxylated linkers and one or more metal containing compounds to form the MOF material.

  6. Porous materials: Lining up metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Champness, Neil R.

    2017-02-01

    A new report demonstrates an innovative approach to aligning crystallites of metal-organic frameworks such that thin films are created with oriented channels -- potentially overcoming one of the major barriers to application of these highly topical materials.

  7. Metal-Organic Frameworks as Platforms for Functional Materials.

    PubMed

    Cui, Yuanjing; Li, Bin; He, Huajun; Zhou, Wei; Chen, Banglin; Qian, Guodong

    2016-03-15

    Discoveries of novel functional materials have played very important roles to the development of science and technologies and thus to benefit our daily life. Among the diverse materials, metal-organic framework (MOF) materials are rapidly emerging as a unique type of porous and organic/inorganic hybrid materials which can be simply self-assembled from their corresponding inorganic metal ions/clusters with organic linkers, and can be straightforwardly characterized by various analytical methods. In terms of porosity, they are superior to other well-known porous materials such as zeolites and carbon materials; exhibiting extremely high porosity with surface area up to 7000 m(2)/g, tunable pore sizes, and metrics through the interplay of both organic and inorganic components with the pore sizes ranging from 3 to 100 Å, and lowest framework density down to 0.13 g/cm(3). Such unique features have enabled metal-organic frameworks to exhibit great potentials for a broad range of applications in gas storage, gas separations, enantioselective separations, heterogeneous catalysis, chemical sensing and drug delivery. On the other hand, metal-organic frameworks can be also considered as organic/inorganic self-assembled hybrid materials, we can take advantages of the physical and chemical properties of both organic and inorganic components to develop their functional optical, photonic, and magnetic materials. Furthermore, the pores within MOFs can also be utilized to encapsulate a large number of different species of diverse functions, so a variety of functional MOF/composite materials can be readily synthesized. In this Account, we describe our recent research progress on pore and function engineering to develop functional MOF materials. We have been able to tune and optimize pore spaces, immobilize specific functional groups, and introduce chiral pore environments to target MOF materials for methane storage, light hydrocarbon separations, enantioselective recognitions

  8. Semiconductor Metal-Organic Frameworks: Future Low-Bandgap Materials.

    PubMed

    Usman, Muhammad; Mendiratta, Shruti; Lu, Kuang-Lieh

    2017-02-01

    Metal-organic frameworks (MOFs) with low density, high porosity, and easy tunability of functionality and structural properties, represent potential candidates for use as semiconductor materials. The rapid development of the semiconductor industry and the continuous miniaturization of feature sizes of integrated circuits toward the nanometer (nm) scale require novel semiconductor materials instead of traditional materials like silicon, germanium, and gallium arsenide etc. MOFs with advantageous properties of both the inorganic and the organic components promise to serve as the next generation of semiconductor materials for the microelectronics industry with the potential to be extremely stable, cheap, and mechanically flexible. Here, a perspective of recent research is provided, regarding the semiconducting properties of MOFs, bandgap studies, and their potential in microelectronic devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Diffusion of Small Molecules in Metal Organic Framework Materials

    NASA Astrophysics Data System (ADS)

    Canepa, Pieremanuele; Nijem, Nour; Chabal, Yves J.; Thonhauser, T.

    2013-01-01

    Ab initio simulations are combined with in situ infrared spectroscopy to unveil the molecular transport of H2, CO2, and H2O in the metal organic framework MOF-74-Mg. Our study uncovers—at the atomistic level—the major factors governing the transport mechanism of these small molecules. In particular, we identify four key diffusion mechanisms and calculate the corresponding diffusion barriers, which are nicely confirmed by time-resolved infrared experiments. We also answer a long-standing question about the existence of secondary adsorption sites for the guest molecules, and we show how those sites affect the macroscopic diffusion properties. Our findings are important to gain a fundamental understanding of the diffusion processes in these nanoporous materials, with direct implications for the usability of MOFs in gas sequestration and storage applications.

  10. Methods for associating or dissociating guest materials with a metal organic framework, systems for associating or dissociating guest materials within a series of metal organic frameworks, thermal energy transfer assemblies, and methods for transferring thermal energy

    DOEpatents

    McGrail, B. Peter; Brown, Daryl R.; Thallapally, Praveen K.

    2014-08-05

    Methods for releasing associated guest materials from a metal organic framework are provided. Methods for associating guest materials with a metal organic framework are also provided. Methods are provided for selectively associating or dissociating guest materials with a metal organic framework. Systems for associating or dissociating guest materials within a series of metal organic frameworks are provided. Thermal energy transfer assemblies are provided. Methods for transferring thermal energy are also provided.

  11. Methods for associating or dissociating guest materials with a metal organic framework, systems for associating or dissociating guest materials within a series of metal organic frameworks, thermal energy transfer assemblies, and methods for transferring thermal energy

    DOEpatents

    McGrail, B. Peter; Brown, Daryl R.; Thallapally, Praveen K.

    2016-08-02

    Methods for releasing associated guest materials from a metal organic framework are provided. Methods for associating guest materials with a metal organic framework are also provided. Methods are provided for selectively associating or dissociating guest materials with a metal organic framework. Systems for associating or dissociating guest materials within a series of metal organic frameworks are provided. Thermal energy transfer assemblies are provided. Methods for transferring thermal energy are also provided.

  12. Metal-organic frameworks as functional, porous materials

    NASA Astrophysics Data System (ADS)

    Rood, Jeffrey A.

    The research presented in this thesis investigates the use of metal carboxylates as permanently porous materials called metal-organic frameworks (MOFs). The project has focused on three broad areas of study, each which strives to develop a further understanding of this class of materials. The first topic is concerned with the synthesis and structural characterization of MOFs. Our group and others have found that the reaction of metal salts with carboxylic acids in polar solvents at elevated temperatures often leads the formation of crystalline MOF materials that can be examined by single crystal X-ray diffraction. Specifically, Chapter 2 reports on some of the first examples of magnesium MOFs, constructed from formate or aryldicarboxylate ligands. The magnesium formate MOF, [Mg3(O2CH) 6] was found to be a permanently porous 3-D material capable of selective uptake and exchange of small molecules. Once the synthesis and structures of some of these materials was known, their physical properties were studied. The magnesium formate MOF, [Mg 3(O2CH)6], was found to be permanently porous and able to reversibly adsorb both N2 and H2 gas. Furthermore, the material was also capable of taking up a variety of organic molecules to form new inclusion compounds that were characterized by XRD studies. Size exclusion was shown for cyclohexane and larger molecules. Chapters 3, 5, and 6 attempt to build off of the synthetic findings reported in Chapter 2. Specifically, the ability of these materials to take up guest molecules is expanded by the attempted synthesis of porous, homochiral MOFs using enantiopure carboxylic acids in the synthesis. It was found that under the appropriate synthetic conditions, both L-tartaric acid and (+)-camphoric acid were robust linkers for the formation of homochiral MOFs. Of the compounds synthesized, the most interesting were the set of compounds, [Zn2(Cam) 2(bipy)⊃3DMF] and [Zn2(Cam)2(apyr)⊃2DMF]. These compounds formed isoreticular cubic

  13. Metal-organic framework materials based on icosahedral boranes and carboranes

    DOEpatents

    Mirkin, Chad A.; Hupp, Joseph T.; Farha, Omar K.; Spokoyny, Alexander M.; Mulfort, Karen L.

    2010-11-02

    Disclosed herein are metal-organic frameworks of metals and boron rich ligands, such as carboranes and icosahedral boranes. Methods of synthesizing and using these materials in gas uptake are disclosed.

  14. Selective Bifunctional Modification of a Non-catenated Metal-Organic Framework Material via 'Click' Chemistry

    SciTech Connect

    Gadzikwa, Tendai; Farha, Omar K.; Malliakas, Christos D.; Kanatzidis, Mercouri G.; Hupp, Joseph T.; Nguyen, SonBinh T.; NWU

    2009-12-01

    A noncatenated, Zn-based metal-organic framework (MOF) material bearing silyl-protected acetylenes was constructed and postsynthetically modified using 'click' chemistry. Using a solvent-based, selective deprotection strategy, two different organic azides were 'clicked' onto the MOF crystals, resulting in a porous material whose internal and external surfaces are differently functionalized.

  15. Lithium-Ion-Battery Anode Materials with Improved Capacity from a Metal-Organic Framework.

    PubMed

    Lin, Xiao-Ming; Niu, Ji-Liang; Lin, Jia; Wei, Lei-Ming; Hu, Lei; Zhang, Gang; Cai, Yue-Peng

    2016-09-06

    We present a porous metal-organic framework (MOF) with remarkable thermal stability that exhibits a discharge capacity of 300 mAh g(-1) as an anode material for a lithium-ion battery. Pyrolysis of the obtained MOF gives an anode material with improved capacity (741 mAh g(-1)) and superior cyclic stability.

  16. Metal-organic frameworks as host materials of confined supercooled liquids.

    PubMed

    Fischer, J K H; Sippel, P; Denysenko, D; Lunkenheimer, P; Volkmer, D; Loidl, A

    2015-10-21

    In this work, we examine the use of metal-organic framework (MOF) systems as host materials for the investigation of glassy dynamics in confined geometry. We investigate the confinement of the molecular glass former glycerol in three MFU-type MOFs with different pore sizes (MFU stands for "Metal-Organic Framework Ulm-University") and study the dynamics of the confined liquid via dielectric spectroscopy. In accord with previous reports on confined glass formers, we find different degrees of deviations from bulk behavior depending on pore size, demonstrating that MOFs are well-suited host systems for confinement investigations.

  17. Metal-organic frameworks as host materials of confined supercooled liquids

    NASA Astrophysics Data System (ADS)

    Fischer, J. K. H.; Sippel, P.; Denysenko, D.; Lunkenheimer, P.; Volkmer, D.; Loidl, A.

    2015-10-01

    In this work, we examine the use of metal-organic framework (MOF) systems as host materials for the investigation of glassy dynamics in confined geometry. We investigate the confinement of the molecular glass former glycerol in three MFU-type MOFs with different pore sizes (MFU stands for "Metal-Organic Framework Ulm-University") and study the dynamics of the confined liquid via dielectric spectroscopy. In accord with previous reports on confined glass formers, we find different degrees of deviations from bulk behavior depending on pore size, demonstrating that MOFs are well-suited host systems for confinement investigations.

  18. Selective Adsorption of Sulfur Dioxide in a Robust Metal-Organic Framework Material.

    PubMed

    Savage, Mathew; Cheng, Yongqiang; Easun, Timothy L; Eyley, Jennifer E; Argent, Stephen P; Warren, Mark R; Lewis, William; Murray, Claire; Tang, Chiu C; Frogley, Mark D; Cinque, Gianfelice; Sun, Junliang; Rudić, Svemir; Murden, Richard T; Benham, Michael J; Fitch, Andrew N; Blake, Alexander J; Ramirez-Cuesta, Anibal J; Yang, Sihai; Schröder, Martin

    2016-10-01

    Selective adsorption of SO2 is realized in a porous metal-organic framework material, and in-depth structural and spectroscopic investigations using X-rays, infrared, and neutrons define the underlying interactions that cause SO2 to bind more strongly than CO2 and N2 .

  19. A Look into PNNL’s New Way of Making Metal Organic Framework Materials (MOFs)

    SciTech Connect

    2016-07-25

    Metal organic framework materials are used in many energy-efficient and green technologies. PNNL researchers may bring their commercial use a step closer to reality by developing a new way to create these materials in larger quantities, better qualities, and more quickly than ever before. This video is a step-by-step look at how our PNNL scientists create MOFs with 80% efficacy.

  20. polyMOFs: A Class of Interconvertible Polymer-Metal-Organic-Framework Hybrid Materials.

    PubMed

    Zhang, Zhenjie; Nguyen, Ha Thi Hoang; Miller, Stephen A; Cohen, Seth M

    2015-05-18

    Preparation of porous materials from one-dimensional polymers is challenging because the packing of polymer chains results in a dense, non-porous arrangement. Herein, we demonstrate the remarkable adaptation of an amorphous, linear, non-porous, flexible organic polymer into a three-dimensional, highly porous, crystalline solid, as the organic component of a metal-organic framework (MOF). A polymer with aromatic dicarboxylic acids in the backbone functioned as a polymer ligand upon annealing with Zn(II), generating a polymer-metal-organic framework (polyMOF). These materials break the dogma that MOFs must be prepared from small, rigid ligands. Similarly, polyMOFs contradict conventional polymer chemistry by demonstrating that linear and amorphous polymers can be readily coaxed into a highly crystalline, porous, three-dimensional structure by coordination chemistry. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Flexibility in metal-organic framework materials: Impact on sorption properties

    NASA Astrophysics Data System (ADS)

    Fletcher, Ashleigh J.; Thomas, K. Mark; Rosseinsky, Matthew J.

    2005-08-01

    Recent years have seen the development of a new class of porous coordination polymers known collectively as metal organic framework materials (MOFs). This review outlines recent progress in understanding how adsorption characteristics of these systems differ from rigid classical sorbents such as activated carbon and zeolites. Gas/vapor adsorption studies for characterization of the porous structures of MOF materials are reviewed and differences in adsorption characteristics based on detailed measurement of equilibrium and dynamical sorption behavior, compared with previous generations of sorbents, are highlighted. The role of framework flexibility and specific structural features, such as windows and pore cavities, within the MOF porous structures are discussed in relation to adsorption mechanisms.

  2. Recent advances in porous polyoxometalate-based metal-organic framework materials.

    PubMed

    Du, Dong-Ying; Qin, Jun-Sheng; Li, Shun-Li; Su, Zhong-Min; Lan, Ya-Qian

    2014-07-07

    Polyoxometalate (POM)-based metal-organic framework (MOF) materials contain POM units and generally generate MOF materials with open networks. POM-based MOF materials, which utilize the advantages of both POMs and MOFs, have received increasing attention, and much effort has been devoted to their preparation and relevant applications over the past few decades. They have good prospects in catalysis owing to the electronic and physical properties of POMs that are tunable by varying constituent elements. In this review, we present recent developments in porous POM-based MOF materials, including their classification, synthesis strategies, and applications, especially in the field of catalysis.

  3. Rational design, synthesis, purification, and activation of metal-organic framework materials.

    PubMed

    Farha, Omar K; Hupp, Joseph T

    2010-08-17

    The emergence of metal-organic frameworks (MOFs) as functional ultrahigh surface area materials is one of the most exciting recent developments in solid-state chemistry. Now constituting thousands of distinct examples, MOFs are an intriguing class of hybrid materials that exist as infinite crystalline lattices with inorganic vertices and molecular-scale organic connectors. Useful properties such as large internal surface areas, ultralow densities, and the availability of uniformly structured cavities and portals of molecular dimensions characterize functional MOFs. Researchers have effectively exploited these unusual properties in applications such as hydrogen and methane storage, chemical separations, and selective chemical catalysis. In principle, one of the most attractive features of MOFs is the simplicity of their synthesis. Typically they are obtained via one-pot solvothermal preparations. However, with the simplicity come challenges. In particular, MOF materials, especially more complex ones, can be difficult to obtain in pure form and with the optimal degree of catenation, the interpenetration or interweaving of identical independent networks. Once these two issues are satisfied, the removal of the guest molecules (solvent from synthesis) without damaging the structural integrity of the material is often an additional challenge. In this Account, we review recent advances in the synthetic design, purification, and activation of metal-organic framework materials. We describe the rational design of a series of organic struts to limit framework catenation and thereby produce large pores. In addition, we demonstrate the rapid separation of desired MOFs from crystalline and amorphous contaminants cogenerated during synthesis based on their different densities. Finally, we discuss the mild and efficient activation of initially solvent-filled pores with supercritical carbon dioxide, yielding usable channels and high internal surface areas. We expect that the

  4. Metal-organic frameworks as cathode materials for Li-O2 batteries.

    PubMed

    Wu, Doufeng; Guo, Ziyang; Yin, Xinbo; Pang, Qingqing; Tu, Binbin; Zhang, Lijuan; Wang, Yong-Gang; Li, Qiaowei

    2014-05-28

    Metal-organic frameworks (MOFs) with open metal sites enrich the population of O2 in the pores significantly and assist the Li-O2 reaction when employed as a cell electrode material. A primary capacity of 9420 mA h g(-1) is achieved in a cell with Mn-MOF-74; more than four times higher than the value obtained in a cell without an MOF. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Metal-organic frameworks as competitive materials for non-linear optics.

    PubMed

    Mingabudinova, L R; Vinogradov, V V; Milichko, V A; Hey-Hawkins, E; Vinogradov, A V

    2016-09-26

    The last five years have witnessed a huge breakthrough in the creation and the study of the properties of a new class of compounds - metamaterials. The next stage of this technological revolution will be the development of active, controllable, and non-linear metamaterials, surpassing natural media as platforms for optical data processing and quantum information applications. However, scientists are constantly faced with the need to find new methods that can ensure the formation of quantum and non-linear metamaterials with higher resolution. One such method of producing metamaterials in the future, which will provide scalability and availability, is chemical synthesis. Meanwhile, the chemical synthesis of organized 3D structures with a period of a few nanometers and a size of up to a few millimeters is not an easy task and is yet to be resolved. The most promising avenue seems to be the use of highly porous structures based on metal-organic frameworks that have demonstrated their unique properties in the field of non-linear optics (NLO) over the past three years. Thus, the aim of this review is to examine current progress and the possibilities of using metal-organic frameworks in the field of non-linear optics as chemically obtained metamaterials of the future. The review begins by presenting the theoretical principles of physical phenomena represented by mathematical descriptions for clarity. Major attention is paid to the second harmonic generation (SHG) effect. In this section we compare inorganic single crystals, which are most commonly used to study the effect in question, to organic materials, which also possess the required properties. Based on these data, we present a rationale for the possibility of studying the non-linear optical properties of metal-organic structures as well as describing the use of synthetic approaches and the difficulties associated with them. The second part of the review explicitly acquaints the reader with a new class of materials

  6. Tetratopic phenyl compounds, related metal-organic framework materials and post-assembly elaboration

    DOEpatents

    Farha, Omar K.; Hupp, Joseph T.

    2012-09-11

    Disclosed are tetratopic carboxylic acid phenyl for use in metal-organic framework compounds. These compounds are useful in catalysis, gas storage, sensing, biological imaging, drug delivery and gas adsorption separation.

  7. Tetratopic phenyl compounds, related metal-organic framework materials and post-assembly elaboration

    DOEpatents

    Farha, Omar K; Hupp, Joseph T

    2013-06-25

    Disclosed are tetratopic carboxylic acid phenyl for use in metal-organic framework compounds. These compounds are useful in catalysis, gas storage, sensing, biological imaging, drug delivery and gas adsorption separation.

  8. Metal-organic frameworks for electronics: emerging second order nonlinear optical and dielectric materials.

    PubMed

    Mendiratta, Shruti; Lee, Cheng-Hua; Usman, Muhammad; Lu, Kuang-Lieh

    2015-10-01

    Metal-organic frameworks (MOFs) have been intensively studied over the past decade because they represent a new category of hybrid inorganic-organic materials with extensive surface areas, ultrahigh porosity, along with the extraordinary tailorability of structure, shape and dimensions. In this highlight, we summarize the current state of MOF research and report on structure-property relationships for nonlinear optical (NLO) and dielectric applications. We focus on the design principles and structural elements needed to develop potential NLO and low dielectric (low-κ) MOFs with an emphasis on enhancing material performance. In addition, we highlight experimental evidence for the design of devices for low-dielectric applications. These results motivate us to develop better low-dielectric and NLO materials and to perform in-depth studies related to deposition techniques, patterning and the mechanical performance of these materials in the future.

  9. Metallated metal-organic frameworks

    DOEpatents

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-08-22

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

  10. Metallated metal-organic frameworks

    DOEpatents

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-02-07

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

  11. Imparting biomolecules to a metal-organic framework material by controlled DNA tetrahedron encapsulation.

    PubMed

    Jia, Yongmei; Wei, Benmei; Duan, Ruixue; Zhang, Ying; Wang, Boya; Hakeem, Abdul; Liu, Nannan; Ou, Xiaowen; Xu, Shaofang; Chen, Zhifei; Lou, Xiaoding; Xia, Fan

    2014-08-04

    Recently, the incorporation of biomolecules in Metal-organic frameworks (MOFs) attracts many attentions because of controlling the functions, properties and stability of trapped molecules. Although there are few reports on protein/MOFs composites and their applications, none of DNA/MOFs composite is reported, as far as we know. Here, we report a new composite material which is self-assembled from 3D DNA (guest) and pre-synthesized MOFs (host) by electrostatic interactions and hydrophilic interactions in a well-dispersed fashion. Its biophysical characterization is well analyzed by fluorescence spectroscopy, quartz crystal microbalance (QCM) and transmission electron microscopy (TEM). This new composite material keeps 3D DNA nanostructure more stable than only 3D DNA nanostructure in DI water at room temperature, and stores amounts of genetic information. It will make DNA as a guest for MOFs and MOFs become a new platform for the development of DNA nanotechnology.

  12. Metal-organic Frameworks as A Tunable Platform for Designing Functional Molecular Materials

    PubMed Central

    Wang, Cheng; Liu, Demin

    2013-01-01

    Metal-organic frameworks (MOFs), also known as coordination polymers, represent an interesting class of crystalline molecular materials that are synthesized by combining metal-connecting points and bridging ligands. The modular nature of and mild conditions for MOF synthesis have permitted the rational structural design of numerous MOFs and the incorporation of various functionalities via constituent building blocks. The resulting designer MOFs have shown promise for applications in a number of areas, including gas storage/separation, nonlinear optics/ferroelectricity, catalysis, energy conversion/storage, chemical sensing, biomedical imaging, and drug delivery. The structure-property relationships of MOFs can also be readily established by taking advantage of the knowledge of their detailed atomic structures, which enables fine-tuning of their functionalities for desired applications. Through the combination of molecular synthesis and crystal engineering MOFs thus present an unprecedented opportunity for the rational and precise design of functional materials. PMID:23944646

  13. Building Nanoporous Metal-Organic Frameworks "Armor" on Fibers for High-Performance Composite Materials.

    PubMed

    Yang, Xiaobin; Jiang, Xu; Huang, Yudong; Guo, Zhanhu; Shao, Lu

    2017-02-15

    The nanoporous metal-organic frameworks (MOFs) "armor" is in situ intergrown onto the surfaces of carbon fibers (CFs) by nitric acid oxidization to supply nucleation sites and serves as a novel interfacial linker between the fiber and polymer matrix and a smart cushion to release interior and exterior applied forces. Simultaneous enhancements of the interfacial and interlaminar shear strength as well as the tensile strength of CFs were achieved. With the aid of an ultrasonic "cleaning" process, the optimized surface energy and tensile strength of CFs with a MOF "armor" are 83.79 mN m(-1) and 5.09 GPa, for an increase of 102% and 11.6%, respectively. Our work finds that the template-induced nucleation of 3D MOF onto 1D fibers is a general and promising approach toward advanced composite materials for diverse applications to meet scientific and technical demands.

  14. Nanoarchitectured Design of Porous Materials and Nanocomposites from Metal-Organic Frameworks.

    PubMed

    Kaneti, Yusuf Valentino; Tang, Jing; Salunkhe, Rahul R; Jiang, Xuchuan; Yu, Aibing; Wu, Kevin C-W; Yamauchi, Yusuke

    2017-03-01

    The emergence of metal-organic frameworks (MOFs) as a new class of crystalline porous materials is attracting considerable attention in many fields such as catalysis, energy storage and conversion, sensors, and environmental remediation due to their controllable composition, structure and pore size. MOFs are versatile precursors for the preparation of various forms of nanomaterials as well as new multifunctional nanocomposites/hybrids, which exhibit superior functional properties compared to the individual components assembling the composites. This review provides an overview of recent developments achieved in the fabrication of porous MOF-derived nanostructures including carbons, metal oxides, metal chalcogenides (metal sulfides and selenides), metal carbides, metal phosphides and their composites. Finally, the challenges and future trends and prospects associated with the development of MOF-derived nanomaterials are also examined. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Explosives in the Cage: Metal-Organic Frameworks for High-Energy Materials Sensing and Desensitization.

    PubMed

    Wang, Shan; Wang, Qianyou; Feng, Xiao; Wang, Bo; Yang, Li

    2017-07-21

    An overview of the current status of coordination polymers and metal-organic frameworks (MOFs) pertaining to the field of energetic materials is provided. The explosive applications of MOFs are discussed from two aspects: one for detection of explosives, and the other for explosive desensitization. By virtue of their adjustable pore/cage sizes, high surface area, tunable functional sites, and rich host-guest chemistry, MOFs have emerged as promising candidates for both explosive sensing and desensitization. The challenges and perspectives in these two areas are thoroughly discussed, and the processing methods for practical applications are also discussed briefly. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Analyzing the frequency shift of physi-adsorbed CO2 in metal organic framework materials

    NASA Astrophysics Data System (ADS)

    Yao, Yanpeng; Nijem, Nour; Li, Jing; Chabal, Yves; Langreth, David; Thonhauser, Timo

    2012-02-01

    Combining first-principles density functional theory simulations with IR and Raman experiments, we determine the frequency shift of vibrational modes of CO2 when physi-adsorbed in the iso-structural metal organic framework materials Mg-MOF74 and Zn-MOF74. Surprisingly, we find that the resulting change in shift is rather different for these two systems and we elucidate possible reasons. We explicitly consider three factors responsible for the frequency shift through physi-absorption, namely (i) the change in the molecule length, (ii) the asymmetric distortion of the CO2 molecule, and (iii) the direct influence of the metal center. The influence of each factor is evaluated separately through different geometry considerations, providing a fundamental understanding of the frequency shifts observed experimentally.

  17. Separation of C2 Hydrocarbons by Porous Materials: Metal Organic Frameworks as Platform

    SciTech Connect

    Banerjee, Debasis; Liu, Jun; Thallapally, Praveen K.

    2014-12-22

    The effective separation of small hydrocarbon molecules (C1 – C4) is an important process for petroleum industry, determining the end price of many essential commodities in our daily lives. Current technologies for separation of these molecules rely on energy intensive fractional distillation processes at cryogenic temperature, which is particularly difficult because of their similar volatility. In retrospect, adsorptive separation using solid state adsorbents might be a cost effective alternative. Several types of solid state adsorbents (e.g. zeolite molecular sieves) were tested for separation of small hydrocarbon molecules as a function of pressure, temperature or vacuum. Among different types of plausible adsorbents, metal organic frameworks (MOFs), a class of porous, crystalline, inorganic-organic hybrid materials, is particularly promising. In this brief comment article, we discuss the separation properties of different types of solid state adsorbents, with a particular emphasis on MOF based adsorbents for separation of C2 hydrocarbon molecules.

  18. Metal-organic frameworks: functional luminescent and photonic materials for sensing applications.

    PubMed

    Lustig, William P; Mukherjee, Soumya; Rudd, Nathan D; Desai, Aamod V; Li, Jing; Ghosh, Sujit K

    2017-06-06

    Metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) are open, crystalline supramolecular coordination architectures with porous facets. These chemically tailorable framework materials are the subject of intense and expansive research, and are particularly relevant in the fields of sensory materials and device engineering. As the subfield of MOF-based sensing has developed, many diverse chemical functionalities have been carefully and rationally implanted into the coordination nanospace of MOF materials. MOFs with widely varied fluorometric sensing properties have been developed using the design principles of crystal engineering and structure-property correlations, resulting in a large and rapidly growing body of literature. This work has led to advancements in a number of crucial sensing domains, including biomolecules, environmental toxins, explosives, ionic species, and many others. Furthermore, new classes of MOF sensory materials utilizing advanced signal transduction by devices based on MOF photonic crystals and thin films have been developed. This comprehensive review summarizes the topical developments in the field of luminescent MOF and MOF-based photonic crystals/thin film sensory materials.

  19. Metal-Organic Frameworks: Literature Survey and Recommendation of Potential Sorbent Materials

    SciTech Connect

    Baumann, T F

    2010-04-29

    Metal-organic frameworks (MOFs) are a special type of porous material with a number of unique properties, including exceptionally high surface areas, large internal pore volumes (void space) and tunable pore sizes. These materials are prepared through the assembly of molecular building blocks into ordered three-dimensional structures. The bulk properties of the MOF are determined by the nature of the building blocks and, as such, these materials can be designed with special characteristics that cannot be realized in other sorbent materials, like activated carbons. For example, MOFs can be constructed with binding sites or pockets that can exhibit selectivity for specific analytes. Alternatively, the framework can be engineered to undergo reversible dimensional changes (or 'breathing') upon interaction with an analyte, effectively trapping the molecule of interest in the lattice structure. In this report, we have surveyed the 4000 different MOF structures reported in the open literature and provided recommendations for specific MOF materials that should be investigated as sorbents for this project.

  20. Strategies for Hydrogen Storage in Nanoporous Metal-Organic Framework Materials

    NASA Astrophysics Data System (ADS)

    Snurr, Randall

    2011-03-01

    Storing hydrogen by physisorption in porous materials is a challenging problem of great interest for future vehicle technology. Metal-organic frameworks (MOFs) are a new class of nanoporous materials that have demonstrated exciting potential for solving this problem. MOFs are synthesized by the self-assembly of metal nodes and connecting organic linker molecules to create stable, porous frameworks. The synthetic chemistry opens the possibility to create an almost unlimited number of MOFs and to tailor them for particular applications, such as hydrogen storage. The diversity of MOFs also creates an opportunity to learn more about the fundamentals of hydrogen adsorption in porous materials. We have used a combination of classical Monte Carlo simulations and quantum mechanical approaches to investigate fundamental questions about hydrogen storage in MOFs and to design new materials with improved storage capabilities. Relationships have been elucidated between hydrogen uptake and properties such as the MOF surface area, void volume, degree of catenation, enthalpy of adsorption, and cation content. Introduction of cations is a promising strategy to improve hydrogen uptake at room temperature, and different metal cations and different strategies for introducing them into MOFs have been screened computationally.

  1. Pore with gate: modulating hydrogen storage in metal-organic framework materials via cation exchange.

    PubMed

    Yang, Sihai; Callear, Samantha K; Ramirez-Cuesta, Anibal J; David, William I F; Sun, Junliang; Blake, Alexander J; Champness, Neil R; Schröder, Martin

    2011-01-01

    A range of anionic metal-organic framework (MOF) materials has been prepared by combination of In(III) with tetracarboxylate isophthalate-based ligands. These materials incorporate organic cations, either H2ppz2+ (ppz = piperazine) or Me2NH2+, that are hydrogen bonded to the pore wall. These cations act as a gate controlling entry of N2 and H2 gas into and out of the porous host. Thus, hysteretic adsorption/desorption for N2 and H2 is observed in these systems, reflecting the role of the bulky hydrogen bonded organic cations in controlling the kinetic trapping of substrates. Post-synthetic cation exchange with Li+ leads to removal of the organic cation and the formation of the corresponding Li+ salts. Replacement of the organic cation with smaller Li+ leads to an increase in internal surface area and pore volume of the framework material, and in some cases to an increase in the isosteric heat of adsorption of H2 at zero coverage, as predicted by theoretical modelling. The structures, characterisation and analysis of these charged porous materials as storage portals for H2 are discussed. Inelastic neutron scattering experiments confirm interaction of H2 with the carboxylate groups of the isophthalate ligands bound to In(III) centres.

  2. Imparting functionality to a metal-organic framework material by controlled nanoparticle encapsulation.

    PubMed

    Lu, Guang; Li, Shaozhou; Guo, Zhen; Farha, Omar K; Hauser, Brad G; Qi, Xiaoying; Wang, Yi; Wang, Xin; Han, Sanyang; Liu, Xiaogang; DuChene, Joseph S; Zhang, Hua; Zhang, Qichun; Chen, Xiaodong; Ma, Jan; Loo, Say Chye Joachim; Wei, Wei D; Yang, Yanhui; Hupp, Joseph T; Huo, Fengwei

    2012-02-19

    Microporous metal-organic frameworks (MOFs) that display permanent porosity show great promise for a myriad of purposes. The potential applications of MOFs can be developed further and extended by encapsulating various functional species (for example, nanoparticles) within the frameworks. However, despite increasing numbers of reports of nanoparticle/MOF composites, simultaneously to control the size, composition, dispersed nature, spatial distribution and confinement of the incorporated nanoparticles within MOF matrices remains a significant challenge. Here, we report a controlled encapsulation strategy that enables surfactant-capped nanostructured objects of various sizes, shapes and compositions to be enshrouded by a zeolitic imidazolate framework (ZIF-8). The incorporated nanoparticles are well dispersed and fully confined within the ZIF-8 crystals. This strategy also allows the controlled incorporation of multiple nanoparticles within each ZIF-8 crystallite. The as-prepared nanoparticle/ZIF-8 composites exhibit active (catalytic, magnetic and optical) properties that derive from the nanoparticles as well as molecular sieving and orientation effects that originate from the framework material.

  3. On the mechanism of hydrogen storage in a metal-organic framework material.

    PubMed

    Belof, Jonathan L; Stern, Abraham C; Eddaoudi, Mohamed; Space, Brian

    2007-12-12

    Monte Carlo simulations were performed modeling hydrogen sorption in a recently synthesized metal-organic framework material (MOF) that exhibits large molecular hydrogen uptake capacity. The MOF is remarkable because at 78 K and 1.0 atm it sorbs hydrogen at a density near that of liquid hydrogen (at 20 K and 1.0 atm) when considering H2 density in the pores. Unlike most other MOFs that have been investigated for hydrogen storage, it has a highly ionic framework and many relatively small channels. The simulations demonstrate that it is both of these physical characteristics that lead to relatively strong hydrogen interactions in the MOF and ultimately large hydrogen uptake. Microscopically, hydrogen interacts with the MOF via three principle attractive potential energy contributions: Van der Waals, charge-quadrupole, and induction. Previous simulations of hydrogen storage in MOFs and other materials have not focused on the role of polarization effects, but they are demonstrated here to be the dominant contribution to hydrogen physisorption. Indeed, polarization interactions in the MOF lead to two distinct populations of dipolar hydrogen that are identified from the simulations that should be experimentally discernible using, for example, Raman spectroscopy. Since polarization interactions are significantly enhanced by the presence of a charged framework with narrow pores, MOFs are excellent hydrogen storage candidates.

  4. Metal-Organic Frameworks as Active Materials in Electronic Sensor Devices.

    PubMed

    Campbell, Michael G; Dincă, Mircea

    2017-05-12

    In the past decade, advances in electrically conductive metal-organic frameworks (MOFs) and MOF-based electronic devices have created new opportunities for the development of next-generation sensors. Here we review this rapidly-growing field, with a focus on the different types of device configurations that have allowed for the use of MOFs as active components of electronic sensor devices.

  5. van der Waals Metal-Organic Framework as an Excitonic Material for Advanced Photonics.

    PubMed

    Milichko, Valentin A; Makarov, Sergey V; Yulin, Alexey V; Vinogradov, Alexandr V; Krasilin, Andrei A; Ushakova, Elena; Dzyuba, Vladimir P; Hey-Hawkins, Evamarie; Pidko, Evgeny A; Belov, Pavel A

    2017-01-23

    Synergistic combination of organic and inorganic nature in van der Waals metal-organic frameworks supports different types of robust excitons that can be effectively and independently manipulated by light at room temperature, and opens new concepts for all-optical data processing and storage.

  6. Imparting high proton conductivity to a metal-organic framework material by controlled acid impregnation.

    PubMed

    Ponomareva, Valentina G; Kovalenko, Konstantin A; Chupakhin, Alexei P; Dybtsev, Danil N; Shutova, Elena S; Fedin, Vladimir P

    2012-09-26

    The extensive implementation of hydrogen-powered technology today is limited by a number of fundamental problems related to materials research. Fuel-cell hydrogen conversion technology requires proton-conducting materials with high conductivity at intermediate temperatures up to 120 °C. The development of such materials remains challenging because the proton transport of many promising candidates is based on extended microstructures of water molecules, which deteriorate at temperatures above the boiling point. Here we show the impregnation of the mesoporous metal-organic framework (MOF) MIL-101 by nonvolatile acids H(2)SO(4) and H(3)PO(4). Such a simple approach affords solid materials with potent proton-conducting properties at moderate temperatures, which is critically important for the proper function of on-board automobile fuel cells. The proton conductivities of the H(2)SO(4)@MIL-101 and H(3)PO(4)@MIL-101 at T = 150 °C and low humidity outperform those of any other MOF-based materials and could be compared with the best proton conductors, such as Nafion.

  7. Surfactant-Mediated Conformal Overgrowth of Core-Shell Metal-Organic Framework Materials with Mismatched Topologies.

    PubMed

    Zhuang, Jia; Chou, Lien-Yang; Sneed, Brian T; Cao, Yingze; Hu, Pan; Feng, Lin; Tsung, Chia-Kuang

    2015-11-04

    Fracture-free and conformal Pd-UiO-66@ZIF-8 core-shell metal-organic framework material is synthesized by a surfactant-mediated method. The hierarchical nanoporous material exhibits great size-selective hydrogenation catalysis and demonstrates potentials for many different applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Structures and Gas Storage Performance of Metal-organic Framework Materials at High Pressures

    NASA Astrophysics Data System (ADS)

    Song, Yang; Hu, Yue; Huang, Yining

    2013-06-01

    Metal Organic Frameworks (MOFs), are crystalline nanoporous materials comprised of small metal clusters connected three-dimensionally by polyfunctional organic ligands. MOFs have been widely studied due to their high porosity, surface area and thermal stability, which make them promising candidates for gas capture and storage. In the MOF family, Zeolitic Imidazolate Frameworks (ZIFs) have attracted much attention because of their promising applications for CO2 storage. In contrast to the extensive studies under ambient conditions, most ZIFs have only been studied under pressure in a very limited range. It is known that pressure can provide an effective driving force to achieve structural modification which includes changes in pore size, opening and geometry, channel shape and internal surface area. Subsequently, these pressure-induced changes will affect the sorption selectivity, capacity and access to the binding sites of the porous materials. Here, we report the first in situ high-pressure investigation of several ZIFs by FTIR spectroscopy. We observed rich pressure-induced transformations upon compression in different pressure ranges. Furthermore, the reversibilities of these transformations upon decompression were also examined. Finally, the performance of CO2 storage of selected ZIFs at high pressures will be addressed. Our observation and analyses contribute to the understanding of chemical and mechanical properties of ZIFs under high-pressure conditions and provide new insight into their storage applications.

  9. Multifunctional, Tunable Metal-Organic Framework Materials Platform for Bioimaging Applications.

    PubMed

    Sava Gallis, Dorina F; Rohwer, Lauren E S; Rodriguez, Mark A; Barnhart-Dailey, Meghan C; Butler, Kimberly S; Luk, Ting S; Timlin, Jerilyn A; Chapman, Karena W

    2017-07-12

    Herein, we describe a novel multifunctional metal-organic framework (MOF) materials platform that displays both porosity and tunable emission properties as a function of the metal identity (Eu, Nd, and tuned compositions of Nd/Yb). Their emission collectively spans the deep red to near-infrared (NIR) spectral region (∼614-1350 nm), which is highly relevant for in vivo bioimaging. These new materials meet important prerequisites as relevant to biological processes: they are minimally toxic to living cells and retain structural integrity in water and phosphate-buffered saline. To assess their viability as optical bioimaging agents, we successfully synthesized the nanoscale Eu analog as a proof-of-concept system in this series. In vitro studies show that it is cell-permeable in individual RAW 264.7 mouse macrophage and HeLa human cervical cancer tissue culture cells. The efficient discrimination between the Eu emission and cell autofluorescence was achieved with hyperspectral confocal fluorescence microscopy, used here for the first time to characterize MOF materials. Importantly, this is the first report that documents the long-term conservation of the intrinsic emission in live cells of a fluorophore-based MOF to date (up to 48 h). This finding, in conjunction with the materials' very low toxicity, validates the biocompatibility in these systems and qualifies them as promising for use in long-term tracking and biodistribution studies.

  10. Water Adsorption in Porous Metal-Organic Frameworks and Related Materials

    SciTech Connect

    Furukawa, H; Gandara, F; Zhang, YB; Jiang, JC; Queen, WL; Hudson, MR; Yaghi, OM

    2014-03-19

    Water adsorption in porous materials is important for many applications such as dehumidification, thermal batteries, and delivery of drinking water in remote areas. In this study, we have identified three criteria for achieving high performing porous materials for water adsorption. These criteria deal with condensation pressure of water in the pores, uptake capacity, and recyclability and water stability of the material. In search of an excellently performing porous material, we have studied and compared the water adsorption properties of 23 materials, 20 of which are metal organic frameworks (MOFs). Among the MOFs are 10 zirconium(IV) MOFs with a subset of these, MOF-801-SC (single crystal form), -802, -805, -806, -808, -812, and -841 reported for the first time. MOF-801-P (microcrystalline powder form) was reported earlier and studied here for its water adsorption properties. MOF-812 was only made and structurally characterized but not examined for water adsorption because it is a byproduct of MOF-841 synthesis. All the new zirconium MOFs are made from the Zr6O4(OH)(4)(-CO2)(n) secondary building units (n = 6, 8, 10, or 12) and variously shaped carboxyl organic linkers to make extended porous frameworks. The permanent porosity of all 23 materials was confirmed and their water adsorption measured to reveal that MOF-801-P and MOF-841 are the highest performers based on the three criteria stated above; they are water stable, do not lose capacity after five adsorption/desorption cycles, and are easily regenerated at room temperature. An X-ray single-crystal study and a powder neutron diffraction study reveal the position of the water adsorption sites in MOF-801 and highlight the importance of the intermolecular interaction between adsorbed water molecules within the pores.

  11. Water adsorption in porous metal-organic frameworks and related materials.

    PubMed

    Furukawa, Hiroyasu; Gándara, Felipe; Zhang, Yue-Biao; Jiang, Juncong; Queen, Wendy L; Hudson, Matthew R; Yaghi, Omar M

    2014-03-19

    Water adsorption in porous materials is important for many applications such as dehumidification, thermal batteries, and delivery of drinking water in remote areas. In this study, we have identified three criteria for achieving high performing porous materials for water adsorption. These criteria deal with condensation pressure of water in the pores, uptake capacity, and recyclability and water stability of the material. In search of an excellently performing porous material, we have studied and compared the water adsorption properties of 23 materials, 20 of which are metal-organic frameworks (MOFs). Among the MOFs are 10 zirconium(IV) MOFs with a subset of these, MOF-801-SC (single crystal form), -802, -805, -806, -808, -812, and -841 reported for the first time. MOF-801-P (microcrystalline powder form) was reported earlier and studied here for its water adsorption properties. MOF-812 was only made and structurally characterized but not examined for water adsorption because it is a byproduct of MOF-841 synthesis. All the new zirconium MOFs are made from the Zr6O4(OH)4(-CO2)n secondary building units (n = 6, 8, 10, or 12) and variously shaped carboxyl organic linkers to make extended porous frameworks. The permanent porosity of all 23 materials was confirmed and their water adsorption measured to reveal that MOF-801-P and MOF-841 are the highest performers based on the three criteria stated above; they are water stable, do not lose capacity after five adsorption/desorption cycles, and are easily regenerated at room temperature. An X-ray single-crystal study and a powder neutron diffraction study reveal the position of the water adsorption sites in MOF-801 and highlight the importance of the intermolecular interaction between adsorbed water molecules within the pores.

  12. Barcoded materials based on photoluminescent hybrid system of lanthanide ions-doped metal organic framework and silica via ion exchange.

    PubMed

    Shen, Xiang; Yan, Bing

    2016-04-15

    A multicolored photoluminescent hybrid system based on lanthanide ions-doped metal organic frameworks/silica composite host has potential in display and barcode applications. By controlling the stoichiometry of the lanthanides via cation exchange, proportional various lanthanide ions are successfully introduced into metal organic frameworks, whose emission intensity is correspondingly proportional to its amount. The resulting luminescent barcodes depend on the lanthanide ions ratios and compositions. Subsequently, the lanthanide ions located in the channels of metal organic frameworks are protected from any interaction with the environment after the modification of silica on the surface. The optical and thermal stability of the hybrid materials are improved for technological application. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. A theoretical and experimental study of hydrogen storage in metal organic framework materials.

    NASA Astrophysics Data System (ADS)

    Cooper, Valentino R.; Lee, Jeong Yong; Li, Jing; Chabal, Yves; Langreth, David C.

    2008-03-01

    Metal-organic framework (MOF) materials, assembled by linking metal ions or clusters through molecular bridges, have been shown to be good candidates for H2 storage. We have been successful in fabricating and characterizing MOFs with increased H2 uptakeootnotetextJ. Y. Lee et al. Adv. Func. Mater., 17, 1255 (2007), though still too low for commercial applications. Here we present a coordinated theoretical-experimental effort to understand the mechanism of H2 adsorption in true MOF materials. Using the completely ab initio van der Waals density functional (vdW-DF)ootnotetextM. Dion et al. Phys. Rev. Lett., 92, 246401 (2004)^,ootnotetextT. Thonhauser et al. Phys. Rev. B, 76, 125112 (2007) we simulate the interactions of H2 within Zn2(bdc)2(ted). We demonstrate that modeling the entire MOF structure can result in different H2 adsorption geometries, binding energies and vibrational frequencies than observed in calculations on fragments of the MOF. Combining these results with experimental IR vibrational frequency studies may provide insights into modifying MOF structure and composition for enhanced H2 uptake.

  14. Creating a Discovery Platform for Confined-Space Chemistry and Materials: Metal-Organic Frameworks.

    SciTech Connect

    Allendorf, Mark D.; Greathouse, Jeffery A.; Simmons, Blake

    2008-09-01

    Metal organic frameworks (MOF) are a recently discovered class of nanoporous, defect-free crystalline materials that enable rational design and exploration of porous materials at the molecular level. MOFs have tunable monolithic pore sizes and cavity environments due to their crystalline nature, yielding properties exceeding those of most other porous materials. These include: the lowest known density (91% free space); highest surface area; tunable photoluminescence; selective molecular adsorption; and methane sorption rivaling gas cylinders. These properties are achieved by coupling inorganic metal complexes such as ZnO4 with tunable organic ligands that serve as struts, allowing facile manipulation of pore size and surface area through reactant selection. MOFs thus provide a discovery platform for generating both new understanding of chemistry in confined spaces and novel sensors and devices based on their unique properties. At the outset of this project in FY06, virtually nothing was known about how to couple MOFs to substrates and the science of MOF properties and how to tune them was in its infancy. An integrated approach was needed to establish the required knowledge base for nanoscale design and develop methodologies integrate MOFs with other materials. This report summarizes the key accomplishments of this project, which include creation of a new class of radiation detection materials based on MOFs, luminescent MOFs for chemical detection, use of MOFs as templates to create nanoparticles of hydrogen storage materials, MOF coatings for stress-based chemical detection using microcantilevers, and "flexible" force fields that account for structural changes in MOFs that occur upon molecular adsorption/desorption. Eight journal articles, twenty presentations at scientific conferences, and two patent applications resulted from the work. The project created a basis for continuing development of MOFs for many Sandia applications and succeeded in securing $2.75 M in

  15. Synthesis and gas adsorption study of porous metal-organic framework materials

    NASA Astrophysics Data System (ADS)

    Mu, Bin

    Metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) have become the focus of intense study over the past decade due to their potential for advancing a variety of applications including air purification, gas storage, adsorption separations, catalysis, gas sensing, drug delivery, and so on. These materials have some distinct advantages over traditional porous materials such as the well-defined structures, uniform pore sizes, chemically functionalized sorption sites, and potential for postsynthetic modification, etc. Thus, synthesis and adsorption studies of porous MOFs have increased substantially in recent years. Among various prospective applications, air purification is one of the most immediate concerns, which has urgent requirements to improve current nuclear, biological, and chemical (NBC) filters involving commercial and military purposes. Thus, the major goal of this funded project is to search, synthesize, and test these novel hybrid porous materials for adsorptive removal of toxic industrial chemicals (TICs) and chemical warfare agents (CWAs), and to install the benchmark for new-generation NBC filters. The objective of this study is three-fold: (i) Advance our understanding of coordination chemistry by synthesizing novel MOFs and characterizing these porous coordination polymers; (ii) Evaluate porous MOF materials for gasadsorption applications including CO2 capture, CH4 storage, other light gas adsorption and separations, and examine the chemical and physical properties of these solid adsorbents including thermal stability and heat capacity of MOFs; (iii) Evaluate porous MOF materials for next-generation NBC filter media by adsorption breakthrough measurements of TICs on MOFs, and advance our understanding about structureproperty relationships of these novel adsorbents.

  16. Study of van der Waals bonding and interactions in metal organic framework materials.

    PubMed

    Zuluaga, Sebastian; Canepa, Pieremanuele; Tan, Kui; Chabal, Yves J; Thonhauser, Timo

    2014-04-02

    Metal organic framework (MOF) materials have attracted a lot of attention due to their numerous applications in fields such as hydrogen storage, carbon capture and gas sequestration. In all these applications, van der Waals forces dominate the interaction between the small guest molecules and the walls of the MOFs. In this review article, we describe how a combined theoretical and experimental approach can successfully be used to study those weak interactions and elucidate the adsorption mechanisms important for various applications. On the theory side, we show that, while standard density functional theory is not capable of correctly describing van der Waals interactions, functionals especially designed to include van der Waals forces exist, yielding results in remarkable agreement with experiment. From the experimental point of view, we show examples in which IR adsorption and Raman spectroscopy are essential to study molecule/MOF interactions. Importantly, we emphasize throughout this review that a combination of theory and experiment is crucial to effectively gain further understanding. In particular, we review such combined studies for the adsorption mechanism of small molecules in MOFs, the chemical stability of MOFs under humid conditions, water cluster formation inside MOFs, and the diffusion of small molecules into MOFs. The understanding of these phenomena is critical for the rational design of new MOFs with desired properties.

  17. Complex Nanostructures from Materials based on Metal-Organic Frameworks for Electrochemical Energy Storage and Conversion.

    PubMed

    Guan, Bu Yuan; Yu, Xin Yao; Wu, Hao Bin; Lou, Xiong Wen David

    2017-09-27

    Metal-organic frameworks (MOFs) have drawn tremendous attention because of their abundant diversity in structure and composition. Recently, there has been growing research interest in deriving advanced nanomaterials with complex architectures and tailored chemical compositions from MOF-based precursors for electrochemical energy storage and conversion. Here, a comprehensive overview of the synthesis and energy-related applications of complex nanostructures derived from MOF-based precursors is provided. After a brief summary of synthetic methods of MOF-based templates and their conversion to desirable nanostructures, delicate designs and preparation of complex architectures from MOFs or their composites are described in detail, including porous structures, single-shelled hollow structures, and multishelled hollow structures, as well as other unusual complex structures. Afterward, their applications are discussed as electrode materials or catalysts for lithium-ion batteries, hybrid supercapacitors, water-splitting devices, and fuel cells. Lastly, the research challenges and possible development directions of complex nanostructures derived from MOF-based-templates for electrochemical energy storage and conversion applications are outlined. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A porous proton-relaying metal-organic framework material that accelerates electrochemical hydrogen evolution

    SciTech Connect

    Hod, Idan; Deria, Pravas; Bury, Wojciech; Mondloch, Joseph E.; Kung, Chung-Wei; So, Monica; Sampson, Matthew D.; Peters, Aaron W.; Kubiak, Cliff P.; Farha, Omar K.; Hupp, Joseph T.

    2015-09-14

    The availability of efficient hydrogen evolution reaction (HER) catalysts is of high importance for solar fuel technologies aimed at reducing future carbon emissions. Even though Pt electrodes are excellent HER electrocatalysts, commercialization of large-scale hydrogen production technology requires finding an equally efficient, low-cost, earth-abundant alternative. Here, high porosity, metal-organic framework (MOF) films have been used as scaffolds for the deposition of a Ni-S electrocatalyst. Compared with an MOF-free Ni-S, the resulting hybrid materials exhibit significantly enhanced performance for HER from aqueous acid, decreasing the kinetic overpotential by more than 200 mV at a benchmark current density of 10 mA cm−2. In conclusion, although the initial aim was to improve electrocatalytic activity by greatly boosting the active area of the Ni-S catalyst, the performance enhancements instead were found to arise primarily from the ability of the proton-conductive MOF to favourably modify the immediate chemical environment of the sulfide-based catalyst.

  19. A porous proton-relaying metal-organic framework material that accelerates electrochemical hydrogen evolution

    DOE PAGES

    Hod, Idan; Deria, Pravas; Bury, Wojciech; ...

    2015-09-14

    The availability of efficient hydrogen evolution reaction (HER) catalysts is of high importance for solar fuel technologies aimed at reducing future carbon emissions. Even though Pt electrodes are excellent HER electrocatalysts, commercialization of large-scale hydrogen production technology requires finding an equally efficient, low-cost, earth-abundant alternative. Here, high porosity, metal-organic framework (MOF) films have been used as scaffolds for the deposition of a Ni-S electrocatalyst. Compared with an MOF-free Ni-S, the resulting hybrid materials exhibit significantly enhanced performance for HER from aqueous acid, decreasing the kinetic overpotential by more than 200 mV at a benchmark current density of 10 mA cm−2. In conclusion, althoughmore » the initial aim was to improve electrocatalytic activity by greatly boosting the active area of the Ni-S catalyst, the performance enhancements instead were found to arise primarily from the ability of the proton-conductive MOF to favourably modify the immediate chemical environment of the sulfide-based catalyst.« less

  20. A porous proton-relaying metal-organic framework material that accelerates electrochemical hydrogen evolution

    PubMed Central

    Hod, Idan; Deria, Pravas; Bury, Wojciech; Mondloch, Joseph E.; Kung, Chung-Wei; So, Monica; Sampson, Matthew D.; Peters, Aaron W.; Kubiak, Cliff P.; Farha, Omar K.; Hupp, Joseph T.

    2015-01-01

    The availability of efficient hydrogen evolution reaction (HER) catalysts is of high importance for solar fuel technologies aimed at reducing future carbon emissions. Even though Pt electrodes are excellent HER electrocatalysts, commercialization of large-scale hydrogen production technology requires finding an equally efficient, low-cost, earth-abundant alternative. Here, high porosity, metal-organic framework (MOF) films have been used as scaffolds for the deposition of a Ni-S electrocatalyst. Compared with an MOF-free Ni-S, the resulting hybrid materials exhibit significantly enhanced performance for HER from aqueous acid, decreasing the kinetic overpotential by more than 200 mV at a benchmark current density of 10 mA cm−2. Although the initial aim was to improve electrocatalytic activity by greatly boosting the active area of the Ni-S catalyst, the performance enhancements instead were found to arise primarily from the ability of the proton-conductive MOF to favourably modify the immediate chemical environment of the sulfide-based catalyst. PMID:26365764

  1. Optochemically Responsive 2D Nanosheets of a 3D Metal-Organic Framework Material.

    PubMed

    Chaudhari, Abhijeet K; Kim, Ha Jin; Han, Intaek; Tan, Jin-Chong

    2017-07-01

    Outstanding functional tunability underpinning metal-organic framework (MOF) confers a versatile platform to contrive next-generation chemical sensors, optoelectronics, energy harvesters, and converters. A rare exemplar of a porous 2D nanosheet material constructed from an extended 3D MOF structure is reported. A rapid supramolecular self-assembly methodology at ambient conditions to synthesize readily exfoliatable MOF nanosheets, functionalized in situ by adopting the guest@MOF (host) strategy, is developed. Nanoscale confinement of light-emitting molecules (as functional guest) inside the MOF pores generates unusual combination of optical, electronic, and chemical properties, arising from the strong host-guest coupling effects. Highly promising photonics-based chemical sensing opened up by the new guest@MOF composite systems is shown. By harnessing host-guest optochemical interactions of functionalized MOF nanosheets, detection of an extensive range of volatile organic compounds and small molecules important for many practical applications has been accomplished. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Preparation and Properties of Metal Organic Framework/Activated Carbon Composite Materials.

    PubMed

    Fleker, Ohad; Borenstein, Arie; Lavi, Ronit; Benisvy, Laurent; Ruthstein, Sharon; Aurbach, Doron

    2016-05-17

    Metal organic frameworks (MOFs) have unique properties that make them excellent candidates for many high-tech applications. Nevertheless, their nonconducting character is an obstacle to their practical utilization in electronic and energy systems. Using the familiar HKUST-1 MOF as a model, we present a new method of imparting electrical conductivity to otherwise nonconducting MOFs by preparing MOF nanoparticles within the conducting matrix of mesoporous activated carbon (AC). This composite material was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), gas adsorption measurements, and electron paramagnetic resonance (EPR) spectroscopy. We show that MOF nanoparticles grown within the carbon matrix maintain their crystalline characteristics and their surface area. Surprisingly, as a result of the composition process, EPR measurements revealed a copper signal that had not yet been achieved. For the first time, we could analyze the complex EPR response of HKUST-1. We demonstrate the high conductivity of the MOF composite and discuss various factors that are responsible for these results. Finally, we present an optional application for using the conductive MOF composite as a high-performance electrode for pseudocapacitors.

  3. A porous proton-relaying metal-organic framework material that accelerates electrochemical hydrogen evolution.

    PubMed

    Hod, Idan; Deria, Pravas; Bury, Wojciech; Mondloch, Joseph E; Kung, Chung-Wei; So, Monica; Sampson, Matthew D; Peters, Aaron W; Kubiak, Cliff P; Farha, Omar K; Hupp, Joseph T

    2015-09-14

    The availability of efficient hydrogen evolution reaction (HER) catalysts is of high importance for solar fuel technologies aimed at reducing future carbon emissions. Even though Pt electrodes are excellent HER electrocatalysts, commercialization of large-scale hydrogen production technology requires finding an equally efficient, low-cost, earth-abundant alternative. Here, high porosity, metal-organic framework (MOF) films have been used as scaffolds for the deposition of a Ni-S electrocatalyst. Compared with an MOF-free Ni-S, the resulting hybrid materials exhibit significantly enhanced performance for HER from aqueous acid, decreasing the kinetic overpotential by more than 200 mV at a benchmark current density of 10 mA cm(-2). Although the initial aim was to improve electrocatalytic activity by greatly boosting the active area of the Ni-S catalyst, the performance enhancements instead were found to arise primarily from the ability of the proton-conductive MOF to favourably modify the immediate chemical environment of the sulfide-based catalyst.

  4. A porous proton-relaying metal-organic framework material that accelerates electrochemical hydrogen evolution

    NASA Astrophysics Data System (ADS)

    Hod, Idan; Deria, Pravas; Bury, Wojciech; Mondloch, Joseph E.; Kung, Chung-Wei; So, Monica; Sampson, Matthew D.; Peters, Aaron W.; Kubiak, Cliff P.; Farha, Omar K.; Hupp, Joseph T.

    2015-09-01

    The availability of efficient hydrogen evolution reaction (HER) catalysts is of high importance for solar fuel technologies aimed at reducing future carbon emissions. Even though Pt electrodes are excellent HER electrocatalysts, commercialization of large-scale hydrogen production technology requires finding an equally efficient, low-cost, earth-abundant alternative. Here, high porosity, metal-organic framework (MOF) films have been used as scaffolds for the deposition of a Ni-S electrocatalyst. Compared with an MOF-free Ni-S, the resulting hybrid materials exhibit significantly enhanced performance for HER from aqueous acid, decreasing the kinetic overpotential by more than 200 mV at a benchmark current density of 10 mA cm-2. Although the initial aim was to improve electrocatalytic activity by greatly boosting the active area of the Ni-S catalyst, the performance enhancements instead were found to arise primarily from the ability of the proton-conductive MOF to favourably modify the immediate chemical environment of the sulfide-based catalyst.

  5. Minerals with metal-organic framework structures.

    PubMed

    Huskić, Igor; Pekov, Igor V; Krivovichev, Sergey V; Friščić, Tomislav

    2016-08-01

    Metal-organic frameworks (MOFs) are an increasingly important family of advanced materials based on open, nanometer-scale metal-organic architectures, whose design and synthesis are based on the directed assembly of carefully designed subunits. We now demonstrate an unexpected link between mineralogy and MOF chemistry by discovering that the rare organic minerals stepanovite and zhemchuzhnikovite exhibit structures found in well-established magnetic and proton-conducting metal oxalate MOFs. Structures of stepanovite and zhemchuzhnikovite, exhibiting almost nanometer-wide and guest-filled apertures and channels, respectively, change the perspective of MOFs as exclusively artificial materials and represent, so far, unique examples of open framework architectures in organic minerals.

  6. Methane storage in metal-organic frameworks.

    PubMed

    He, Yabing; Zhou, Wei; Qian, Guodong; Chen, Banglin

    2014-08-21

    Natural gas (NG), whose main component is methane, is an attractive fuel for vehicular applications. Realization of safe, cheap and convenient means and materials for high-capacity methane storage can significantly facilitate the implementation of natural gas fuelled vehicles. The physisorption based process involving porous materials offers an efficient storage methodology and the emerging porous metal-organic frameworks have been explored as potential candidates because of their extraordinarily high porosities, tunable pore/cage sizes and easily immobilized functional sites. In this view, we provide an overview of the current status of metal-organic frameworks for methane storage.

  7. Binding energies of hydrogen molecules to isoreticular metal-organic framework materials.

    PubMed

    Sagara, Tatsuhiko; Klassen, James; Ortony, Julia; Ganz, Eric

    2005-07-01

    Recently, several novel isoreticular metal-organic framework (IRMOF) structures have been fabricated and tested for hydrogen storage applications. To improve our understanding of these materials, and to promote quantitative calculations and simulations, the binding energies of hydrogen molecules to the MOF have been studied. High-quality second-order Moller-Plesset (MP2) calculations using the resolution of the identity approximation and the quadruple zeta QZVPP basis set were used. These calculations use terminated molecular fragments from the MOF materials. For H2 on the zinc oxide corners, the MP2 binding energy using Zn4O(HCO2)6 molecule is 6.28 kJ/mol. For H2 on the linkers, the binding energy is calculated using lithium-terminated molecular fragments. The MP2 results with coupled-cluster singles and doubles and noniterative triples method corrections and charge-transfer corrections are 4.16 kJ/mol for IRMOF-1, 4.72 kJ/mol for IRMOF-3, 4.86 kJ/mol for IRMOF-6, 4.54 kJ/mol for IRMOF-8, 5.50 and 4.90 kJ/mol for IRMOF-12, 4.87 and 4.84 kJ/mol for IRMOF-14, 5.42 kJ/mol for IRMOF-18, and 4.97 and 4.66 kJ/mol for IRMOF-993. The larger linkers are all able to bind multiple hydrogen molecules per side. The linkers of IRMOF-12, IRMOF-993, and IRMOF-14 can bind two to three, three, and four hydrogen molecules per side, respectively. In general, the larger linkers have the largest binding energies, and, together with the enhanced surface area available for binding, will provide increased hydrogen storage. We also find that adding up NH2 or CH3 groups to each linker can provide up to a 33% increase in the binding energy.

  8. Binding energies of hydrogen molecules to isoreticular metal-organic framework materials

    NASA Astrophysics Data System (ADS)

    Sagara, Tatsuhiko; Klassen, James; Ortony, Julia; Ganz, Eric

    2005-07-01

    Recently, several novel isoreticular metal-organic framework (IRMOF) structures have been fabricated and tested for hydrogen storage applications. To improve our understanding of these materials, and to promote quantitative calculations and simulations, the binding energies of hydrogen molecules to the MOF have been studied. High-quality second-order Møller-Plesset (MP2) calculations using the resolution of the identity approximation and the quadruple zeta QZVPP basis set were used. These calculations use terminated molecular fragments from the MOF materials. For H2 on the zinc oxide corners, the MP2 binding energy using Zn4O(HCO2)6 molecule is 6.28kJ/mol. For H2 on the linkers, the binding energy is calculated using lithium-terminated molecular fragments. The MP2 results with coupled-cluster singles and doubles and noniterative triples method corrections and charge-transfer corrections are 4.16kJ/mol for IRMOF-1, 4.72kJ/mol for IRMOF-3, 4.86kJ/mol for IRMOF-6, 4.54kJ/mol for IRMOF-8, 5.50 and 4.90kJ/mol for IRMOF-12, 4.87 and 4.84kJ/mol for IRMOF-14, 5.42kJ/mol for IRMOF-18, and 4.97 and 4.66kJ/mol for IRMOF-993. The larger linkers are all able to bind multiple hydrogen molecules per side. The linkers of IRMOF-12, IRMOF-993, and IRMOF-14 can bind two to three, three, and four hydrogen molecules per side, respectively. In general, the larger linkers have the largest binding energies, and, together with the enhanced surface area available for binding, will provide increased hydrogen storage. We also find that adding up NH2 or CH3 groups to each linker can provide up to a 33% increase in the binding energy.

  9. "Clickable" metal-organic framework.

    PubMed

    Goto, Yuta; Sato, Hiroki; Shinkai, Seiji; Sada, Kazuki

    2008-11-05

    We demonstrated the metal-organic framework bearing the azide group in the organic linkers and in situ click reactions with some small alkynes. The XRPD patterns indicated that the click reaction proceeded without any decomposition of the original MOF network. Controlling the organic linkers and incorporation of the azide groups should provide the designer-made MOFs that have controlled molecular cavities with the desired steric dimensions and functionality.

  10. Metal-organic framework templated synthesis of porous inorganic materials as novel sorbents

    DOEpatents

    Taylor-Pashow, Kathryn M. L.; Lin, Wenbin; Abney, Carter W.

    2017-03-21

    A novel metal-organic framework (MOF) templated process for the synthesis of highly porous inorganic sorbents for removing radionuclides, actinides, and heavy metals is disclosed. The highly porous nature of the MOFs leads to highly porous inorganic sorbents (such as oxides, phosphates, sulfides, etc) with accessible surface binding sites that are suitable for removing radionuclides from high level nuclear wastes, extracting uranium from acid mine drainage and seawater, and sequestering heavy metals from waste streams. In some cases, MOFs can be directly used for removing these metal ions as MOFs are converted to highly porous inorganic sorbents in situ.

  11. De novo synthesis of a metal-organic framework material featuring ultrahigh surface area and gas storage capacities.

    PubMed

    Farha, Omar K; Yazaydın, A Özgür; Eryazici, Ibrahim; Malliakas, Christos D; Hauser, Brad G; Kanatzidis, Mercouri G; Nguyen, SonBinh T; Snurr, Randall Q; Hupp, Joseph T

    2010-11-01

    Metal-organic frameworks--a class of porous hybrid materials built from metal ions and organic bridges--have recently shown great promise for a wide variety of applications. The large choice of building blocks means that the structures and pore characteristics of the metal-organic frameworks can be tuned relatively easily. However, despite much research, it remains challenging to prepare frameworks specifically tailored for particular applications. Here, we have used computational modelling to design and predictively characterize a metal-organic framework (NU-100) with a particularly high surface area. Subsequent experimental synthesis yielded a material, matching the calculated structure, with a high BET surface area (6,143 m(2) g(-1)). Furthermore, sorption measurements revealed that the material had high storage capacities for hydrogen (164 mg g(-1)) and carbon dioxide (2,315 mg g(-1))--gases of high importance in the contexts of clean energy and climate alteration, respectively--in excellent agreement with predictions from modelling.

  12. Superhydrophobic perfluorinated metal-organic frameworks.

    PubMed

    Chen, Teng-Hao; Popov, Ilya; Zenasni, Oussama; Daugulis, Olafs; Miljanić, Ognjen Š

    2013-08-07

    Three perfluorinated Cu-based metal-organic frameworks (MOFs) were prepared starting from extensively fluorinated biphenyl-based ligands accessed via C-H functionalization. These new materials are highly hydrophobic: with water contact angles of up to 151 ± 1°, they are among the most water-repellent MOFs ever reported.

  13. Multifunctional Supramolecular Hybrid Materials Constructed from Hierarchical Self-Ordering of In Situ Generated Metal-Organic Framework (MOF) Nanoparticles.

    PubMed

    Chaudhari, Abhijeet K; Han, Intaek; Tan, Jin-Chong

    2015-06-25

    A synergistic approach is described to engineer supramolecular hybrid materials based on metal-organic frameworks, encompassing HKUST-1 nanoparticles formed in situ, coexisting with an electrically conducting gel fiber network. Following findings were made: (a) multistimuli-responsive structural transformation via reversible sol-gel switching, and (b) radical conversion of a soft hybrid gel into a mechanically malleable, viscoelastic matter. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Theoretical and experimental analysis of H2 binding in a prototypical metal-organic framework material

    NASA Astrophysics Data System (ADS)

    Kong, Lingzhu; Cooper, Valentino R.; Nijem, Nour; Li, Kunhao; Li, Jing; Chabal, Yves J.; Langreth, David C.

    2009-02-01

    Hydrogen adsorption by the metal-organic framework (MOF) structure Zn2(BDC)2(TED) is investigated using a combination of experimental and theoretical methods. By using the nonempirical van der Waals density-functional approach, it is found that the locus of deepest H2 binding positions lies within two types of narrow channel. The energies of the most stable binding sites, as well as the number of such binding sites, are consistent with the values obtained from experimental adsorption isotherms and heat of adsorption data. Calculations of the shift of the H-H stretch frequency when adsorbed in the MOF give a value of approximately -30cm-1 at the strongest binding point in each of the two channels. Ambient temperature infrared-absorption spectroscopy measurements give a hydrogen peak centered at 4120cm-1 , implying a shift consistent with the theoretical calculations.

  15. Materials design by evolutionary optimization of functional groups in metal-organic frameworks.

    PubMed

    Collins, Sean P; Daff, Thomas D; Piotrkowski, Sarah S; Woo, Tom K

    2016-11-01

    A genetic algorithm that efficiently optimizes a desired physical or functional property in metal-organic frameworks (MOFs) by evolving the functional groups within the pores has been developed. The approach has been used to optimize the CO2 uptake capacity of 141 experimentally characterized MOFs under conditions relevant for postcombustion CO2 capture. A total search space of 1.65 trillion structures was screened, and 1035 derivatives of 23 different parent MOFs were identified as having exceptional CO2 uptakes of >3.0 mmol/g (at 0.15 atm and 298 K). Many well-known MOF platforms were optimized, with some, such as MIL-47, having their CO2 adsorption increase by more than 400%. The structures of the high-performing MOFs are provided as potential targets for synthesis.

  16. Materials design by evolutionary optimization of functional groups in metal-organic frameworks

    PubMed Central

    Collins, Sean P.; Daff, Thomas D.; Piotrkowski, Sarah S.; Woo, Tom K.

    2016-01-01

    A genetic algorithm that efficiently optimizes a desired physical or functional property in metal-organic frameworks (MOFs) by evolving the functional groups within the pores has been developed. The approach has been used to optimize the CO2 uptake capacity of 141 experimentally characterized MOFs under conditions relevant for postcombustion CO2 capture. A total search space of 1.65 trillion structures was screened, and 1035 derivatives of 23 different parent MOFs were identified as having exceptional CO2 uptakes of >3.0 mmol/g (at 0.15 atm and 298 K). Many well-known MOF platforms were optimized, with some, such as MIL-47, having their CO2 adsorption increase by more than 400%. The structures of the high-performing MOFs are provided as potential targets for synthesis. PMID:28138523

  17. Temperature-/pressure-dependent selective separation of CO(2) or benzene in a chiral metal-organic framework material.

    PubMed

    Tan, Yan-Xi; He, Yan-Ping; Zhang, Jian

    2012-08-01

    Presented here is a chiral microporous metal-organic framework material with a three-fold interpenetrating diamond-type structural topology and interesting properties for selective separation. The material has a high storage capacity for CO(2) gas (4.23 mmol g(-1) at 273 K and 1 bar) and shows fantastic temperature-dependent selectivity for CO(2) over N(2). Moreover, this multifunctional material, which has a rich π system, can selectively adsorb benzene over cyclohexane at low pressure (0.05 bar) at 298 K.

  18. Experimental Evidence Supported by Simulations of a Very High H2 Diffusion in Metal Organic Framework Materials

    NASA Astrophysics Data System (ADS)

    Salles, F.; Jobic, H.; Maurin, G.; Koza, M. M.; Llewellyn, P. L.; Devic, T.; Serre, C.; Ferey, G.

    2008-06-01

    Quasielastic neutron scattering measurements are combined with molecular dynamics simulations to extract the self-diffusion coefficient of hydrogen in the metal organic frameworks MIL-47(V) and MIL-53(Cr). We find that the diffusivity of hydrogen at low loading is about 2 orders of magnitude higher than in zeolites. Such a high mobility has never been experimentally observed before in any nanoporous materials, although it was predicted in carbon nanotubes. Either 1D or 3D diffusion mechanisms are elucidated depending on the chemical features of the MIL framework.

  19. Experimental Evidence Supported by Simulations of a Very High H{sub 2} Diffusion in Metal Organic Framework Materials

    SciTech Connect

    Salles, F.; Maurin, G.; Jobic, H.; Koza, M. M.; Llewellyn, P. L.; Devic, T.; Serre, C.; Ferey, G.

    2008-06-20

    Quasielastic neutron scattering measurements are combined with molecular dynamics simulations to extract the self-diffusion coefficient of hydrogen in the metal organic frameworks MIL-47(V) and MIL-53(Cr). We find that the diffusivity of hydrogen at low loading is about 2 orders of magnitude higher than in zeolites. Such a high mobility has never been experimentally observed before in any nanoporous materials, although it was predicted in carbon nanotubes. Either 1D or 3D diffusion mechanisms are elucidated depending on the chemical features of the MIL framework.

  20. Recent applications of metal-organic frameworks in sample pretreatment.

    PubMed

    Wang, Yonghua; Rui, Min; Lu, Guanghua

    2017-06-19

    Metal-organic frameworks are promising materials in diverse analytical applications especially in sample pretreatment by virtue of their diverse structure topology, tunable pore size, permanent nanoscale porosity, high surface area, and good thermostability. According to hydrostability, metal-organic frameworks are divided into moisture-sensitive and water-stable types. In the actual applications, both kinds of metal-organic frameworks are usually engineered into hybrid composites containing magnetite, silicon dioxide, graphene, or directly carbonized to metal-organic frameworks derived carbon. These metal-organic frameworks based materials show good extraction performance to environmental pollutants. This review provides a critical overview of the applications of metal-organic frameworks and their composites in sample pretreatment modes, that is, solid-phase extraction, magnetic solid-phase extraction, micro-solid-phase extraction, solid-phase microextraction, and stir bar solid extraction. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Metal-organic framework nanosheets in polymer composite materials for gas separation

    PubMed Central

    Seoane, Beatriz; Miro, Hozanna; Corma, Avelino; Kapteijn, Freek; Llabrés i Xamena, Francesc X.; Gascon, Jorge

    2014-01-01

    Composites incorporating two-dimensional nanostructures within polymeric matrices hold potential as functional components for several technologies, including gas separation. Prospectively, employing metal-organic-frameworks (MOFs) as versatile nanofillers would notably broaden the scope of functionalities. However, synthesizing MOFs in the form of free standing nanosheets has proven challenging. We present a bottom-up synthesis strategy for dispersible copper 1,4-benzenedicarboxylate MOF lamellae of micrometer lateral dimensions and nanometer thickness. Incorporating MOF nanosheets into polymer matrices endows the resultant composites with outstanding CO2 separation performance from CO2/CH4 gas mixtures, together with an unusual and highly desired increment in the separation selectivity with pressure. As revealed by tomographic focused-ion-beam scanning-electron-microscopy, the unique separation behaviour stems from a superior occupation of the membrane cross-section by the MOF nanosheets as compared to isotropic crystals, which improves the efficiency of molecular discrimination and eliminates unselective permeation pathways. This approach opens the door to ultrathin MOF-polymer composites for various applications. PMID:25362353

  2. Lanthanide metal-organic frameworks as selective microporous materials for adsorption of heavy metal ions.

    PubMed

    Jamali, Abbas; Tehrani, Alireza Azhdari; Shemirani, Farzaneh; Morsali, Ali

    2016-06-14

    Four microporous lanthanide metal-organic frameworks (MOFs), namely Ln(BTC)(H2O)(DMF)1.1 (Ln = Tb, Dy, Er and Yb, DMF = dimethylformamide, H3BTC = benzene-1,3,5-tricarboxylic acid), have been used for selective adsorption of Pb(ii) and Cu(ii). Among these MOFs, the Dy-based MOF shows better adsorption property and selectivity toward Pb(ii) and Cu(ii) ions. Adsorption isotherms indicate that sorption of Pb(ii) and Cu(ii) on MOFs is via monolayer coverage. Preconcentration is based on solid-phase extraction in which MOFs were rapidly injected into water samples and adsorption of metal ions was rapid because of good contact with analyte; then adsorbed Pb(ii) and Cu(ii) ions were analyzed by FAAS. The optimized methodology represents good linearity between 1 and 120 μg L(-1) and detection limit of 0.4 and 0.26 μg L(-1) for Pb(ii) and Cu(ii), respectively. Subsequently the method was evaluated for preconcentration of target metal ions in some environmental water samples.

  3. Minerals with metal-organic framework structures

    PubMed Central

    Huskić, Igor; Pekov, Igor V.; Krivovichev, Sergey V.; Friščić, Tomislav

    2016-01-01

    Metal-organic frameworks (MOFs) are an increasingly important family of advanced materials based on open, nanometer-scale metal-organic architectures, whose design and synthesis are based on the directed assembly of carefully designed subunits. We now demonstrate an unexpected link between mineralogy and MOF chemistry by discovering that the rare organic minerals stepanovite and zhemchuzhnikovite exhibit structures found in well-established magnetic and proton-conducting metal oxalate MOFs. Structures of stepanovite and zhemchuzhnikovite, exhibiting almost nanometer-wide and guest-filled apertures and channels, respectively, change the perspective of MOFs as exclusively artificial materials and represent, so far, unique examples of open framework architectures in organic minerals. PMID:27532051

  4. Nanoscale metal-organic materials.

    PubMed

    Carné, Arnau; Carbonell, Carlos; Imaz, Inhar; Maspoch, Daniel

    2011-01-01

    Metal-organic materials are found to be a fascinating novel class of functional nanomaterials. The limitless combinations between inorganic and organic building blocks enable researchers to synthesize 0- and 1-D metal-organic discrete nanostructures with varied compositions, morphologies and sizes, fabricate 2-D metal-organic thin films and membranes, and even structure them on surfaces at the nanometre length scale. In this tutorial review, the synthetic methodologies for preparing these miniaturized materials as well as their potential properties and future applications are discussed. This review wants to offer a panoramic view of this embryonic class of nanoscale materials that will be of interest to a cross-section of researchers working in chemistry, physics, medicine, nanotechnology, materials chemistry, etc., in the next years.

  5. Molecular simulations for energy, environmental and pharmaceutical applications of nanoporous materials: from zeolites, metal-organic frameworks to protein crystals.

    PubMed

    Jiang, Jianwen; Babarao, Ravichandar; Hu, Zhongqiao

    2011-07-01

    Nanoporous materials have widespread applications in chemical industry, but the pathway from laboratory synthesis and testing to practical utilization of nanoporous materials is substantially challenging and requires fundamental understanding from the bottom up. With ever-growing computational resources, molecular simulations have become an indispensable tool for material characterization, screening and design. This tutorial review summarizes the recent simulation studies in zeolites, metal-organic frameworks and protein crystals, and provides a molecular overview for energy, environmental and pharmaceutical applications of nanoporous materials with increasing degree of complexity in building blocks. It is demonstrated that molecular-level studies can bridge the gap between physical and engineering sciences, unravel microscopic insights that are otherwise experimentally inaccessible, and assist in the rational design of new materials. The review is concluded with major challenges in future simulation exploration of novel nanoporous materials for emerging applications.

  6. Gas adsorption and structural diversity in a family of Cu(II) pyridyl-isophthalate metal-organic framework materials

    NASA Astrophysics Data System (ADS)

    Gould, Jamie A.; Athwal, Harprit Singh; Blake, Alexander J.; Lewis, William; Hubberstey, Peter; Champness, Neil R.; Schröder, Martin

    2017-01-01

    A family of Cu(II)-based metal-organic frameworks (MOFs) has been synthesized using three pyridyl-isophthalate ligands, H2L1 (4'-(pyridin-4-yl)biphenyl-3,5-dicarboxylic acid), H2L2 (4''-(pyridin-4-yl)-1,1':4',1''-terphenyl-3,5-dicarboxylic acid) and H2L3 (5-[4-(pyridin-4-yl)naphthalen-1-yl]benzene-1,3-dicarboxylic acid). Although in each case the pyridyl-isophthalate ligands adopt the same pseudo-octahedral [Cu2(O2CR)4N2] paddlewheel coordination modes, the resulting frameworks are structurally diverse, particularly in the case of the complex of Cu(II) with H2L3, which leads to three distinct supramolecular isomers, each derived from Kagomé and square nets. In contrast to [Cu(L2)] and the isomers of [Cu(L3)], [Cu(L1)] exhibits permanent porosity. Thus, the gas adsorption properties of [Cu(L1)] were investigated with N2, CO2 and H2, and the material exhibits an isosteric heat of adsorption competitive with leading MOF sorbents for CO2. [Cu(L1)] displays high H2 adsorption, with the density in the pores approaching that of liquid H2. This article is part of the themed issue 'Coordination polymers and metal-organic frameworks: materials by design'.

  7. Gas adsorption and structural diversity in a family of Cu(II) pyridyl-isophthalate metal-organic framework materials.

    PubMed

    Gould, Jamie A; Athwal, Harprit Singh; Blake, Alexander J; Lewis, William; Hubberstey, Peter; Champness, Neil R; Schröder, Martin

    2017-01-13

    A family of Cu(II)-based metal-organic frameworks (MOFs) has been synthesized using three pyridyl-isophthalate ligands, H2L(1) (4'-(pyridin-4-yl)biphenyl-3,5-dicarboxylic acid), H2L(2) (4''-(pyridin-4-yl)-1,1':4',1''-terphenyl-3,5-dicarboxylic acid) and H2L(3) (5-[4-(pyridin-4-yl)naphthalen-1-yl]benzene-1,3-dicarboxylic acid). Although in each case the pyridyl-isophthalate ligands adopt the same pseudo-octahedral [Cu2(O2CR)4N2] paddlewheel coordination modes, the resulting frameworks are structurally diverse, particularly in the case of the complex of Cu(II) with H2L(3), which leads to three distinct supramolecular isomers, each derived from Kagomé and square nets. In contrast to [Cu(L(2))] and the isomers of [Cu(L(3))], [Cu(L(1))] exhibits permanent porosity. Thus, the gas adsorption properties of [Cu(L(1))] were investigated with N2, CO2 and H2, and the material exhibits an isosteric heat of adsorption competitive with leading MOF sorbents for CO2 [Cu(L(1))] displays high H2 adsorption, with the density in the pores approaching that of liquid H2This article is part of the themed issue 'Coordination polymers and metal-organic frameworks: materials by design'. © 2016 The Author(s).

  8. Preparation and applications of novel composites composed of metal-organic frameworks and two-dimensional materials.

    PubMed

    Li, Shaozhou; Yang, Kai; Tan, Chaoliang; Huang, Xiao; Huang, Wei; Zhang, Hua

    2016-01-28

    Metal-organic frameworks (MOFs), an emerging type of porous crystalline materials, have received increasing attention in recent years due to their compositional, structural and chemical versatility. Moreover, great progress has been made in the fundamental study and technological development of two-dimensional (2D) materials, such as graphene and metal dichalcogenide nanosheets, which exhibit a number of unique and attractive properties for wide applications. Recently, the smart integration of the aforementioned two types of functional materials, i.e. MOFs and 2D materials, has led to improved performance in molecular absorption, separation and storage, and shown promise in selective catalysis and biosensing. This feature article aims at providing a brief introduction to the composites composed of MOFs and 2D materials, focusing mainly on their preparation methods and applications. Finally, technical challenges and future opportunities in this field will also be discussed.

  9. Selective adsorption of sulfur dioxide in a robust metal-organic framework material

    DOE PAGES

    Savage, Mathew; Cheng, Yongqiang; Easun, Timothy L.; ...

    2016-08-16

    Here, selective adsorption of SO2 is realized in a porous metal–organic framework material, and in-depth structural and spectroscopic investigations using X-rays, infrared, and neutrons define the underlying interactions that cause SO2 to bind more strongly than CO2 and N2.

  10. Hydrogen storage studies on palladium-doped carbon materials (AC, CB, CNMs) @ metal-organic framework-5.

    PubMed

    Viditha, V; Srilatha, K; Himabindu, V

    2016-05-01

    Metal organic frameworks (MOFs) are a rapidly growing class of porous materials and are considered as best adsorbents for their high surface area and extraordinary porosity. The MOFs are synthesized by using various chemicals like triethylamine, terepthalic acid, zinc acetate dihydrate, chloroform, and dimethylformamide (DMF). Synthesized MOFs are intercalated with palladium/activated carbon, carbon black, and carbon nanomaterials by chemical reduction method for the purpose of enhancing the hydrogen adsorption capacities. We have observed that the palladium doped activated carbon on MOF-5 showed high hydrogen storage capacity. This may be due to the affinity of the palladium toward hydrogen molecule. The samples are characterized by X-ray diffraction, scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. We have observed a clear decrease in the BET surface area and pore volume. The obtained results show a better performance for the synthesized sample. To our best knowledge, no one has reported the work on palladium-doped carbon materials (activated carbon, carbon black, carbon nanomaterials) impregnated to the metal-organic framework-5. We have attempted to synthesize carbon nanomaterials using indigenously fabricated chemical vapor deposition (CVD) unit as a support. We have observed an increase in the hydrogen storage capacities.

  11. Multiaxis sensing using metal organic frameworks

    DOEpatents

    Talin, Albert Alec; Allendorf, Mark D.; Leonard, Francois; Stavila, Vitalie

    2017-01-17

    A sensor device including a sensor substrate; and a thin film comprising a porous metal organic framework (MOF) on the substrate that presents more than one transduction mechanism when exposed to an analyte. A method including exposing a porous metal organic framework (MOF) on a substrate to an analyte; and identifying more than one transduction mechanism in response to the exposure to the analyte.

  12. Gas Phase Sensing of Alcohols by Metal Organic Framework-Polymer Composite Materials.

    PubMed

    Sachdeva, Sumit; Koper, Sander J H; Sabetghadam, Anahid; Soccol, Dimitri; Gravesteijn, Dirk J; Kapteijn, Freek; Sudhölter, Ernst J R; Gascon, Jorge; de Smet, Louis C P M

    2017-07-26

    Affinity layers play a crucial role in chemical sensors for the selective and sensitive detection of analytes. Here, we report the use of composite affinity layers containing Metal Organic Frameworks (MOFs) in a polymeric matrix for sensing purposes. Nanoparticles of NH2-MIL-53(Al) were dispersed in a Matrimid polymer matrix with different weight ratios (0-100 wt %) and drop-casted on planar capacitive transducer devices. These coated devices were electrically analyzed using impedance spectroscopy and investigated for their sensing properties toward the detection of a series of alcohols and water in the gas phase. The measurements indicated a reversible and reproducible response in all devices. Sensor devices containing 40 wt % NH2-MIL-53(Al) in Matrimid showed a maximum response for methanol and water. The sensor response time slowed down with increasing MOF concentration until 40 wt %. The half time of saturation response (τ0.5) increased by ∼1.75 times for the 40 wt % composition compared to devices coated with Matrimid only. This is attributed to polymer rigidification near the MOF/polymer interface. Higher MOF loadings (≥50 wt %) resulted in brittle coatings with a response similar to the 100 wt % MOF coating. Cross-sensitivity studies showed the ability to kinetically distinguish between the different alcohols with a faster response for methanol and water compared to ethanol and 2-propanol. The observed higher affinity of the pure Matrimid polymer toward methanol compared to water allows also for a higher uptake of methanol in the composite matrices. Also, as indicated by the sensing studies with a mixture of water and methanol, the methanol uptake is independent of the presence of water up to 6000 ppm of water. The NH2-MIL-53(Al) MOFs dispersed in the Matrimid matrix show a sensitive and reversible capacitive response, even in the presence of water. By tuning the precise compositions, the affinity kinetics and overall affinity can be tuned, showing the

  13. Gas adsorption on metal-organic frameworks

    DOEpatents

    Willis, Richard R [Cary, IL; Low, John J. , Faheem, Syed A.; Benin, Annabelle I [Oak Forest, IL; Snurr, Randall Q [Evanston, IL; Yazaydin, Ahmet Ozgur [Evanston, IL

    2012-07-24

    The present invention involves the use of certain metal organic frameworks that have been treated with water or another metal titrant in the storage of carbon dioxide. The capacity of these frameworks is significantly increased through this treatment.

  14. Polymer-Metal-Organic Frameworks (polyMOFs) as Water Tolerant Materials for Selective Carbon Dioxide Separations.

    PubMed

    Zhang, Zhenjie; Nguyen, Ha Thi Hoang; Miller, Stephen A; Ploskonka, Ann M; DeCoste, Jared B; Cohen, Seth M

    2016-01-27

    Recently, polymer-metal-organic frameworks (polyMOFs) were reported as a new class of hybrid porous materials that combine advantages of both organic polymers and crystalline MOFs. Herein, we report a bridging coligand strategy to prepare new types of polyMOFs, demonstrating that polyMOFs are compatible with additional MOF architectures besides that of the earlier reported IRMOF-1 type polyMOF. Gas sorption studies revealed that these polyMOF materials exhibited relatively high CO2 sorption but very low N2 sorption, making them promising materials for CO2/N2 separations. Moreover, these polyMOFs demonstrated exceptional water stability attributed to the hydrophobicity of polymer ligands as well as the cross-linking of the polymer chains within the MOF.

  15. Metal-organic frameworks in chromatography.

    PubMed

    Yusuf, Kareem; Aqel, Ahmad; ALOthman, Zeid

    2014-06-27

    Metal-organic frameworks (MOFs) emerged approximately two decades ago and are the youngest class of porous materials. Despite their short existence, MOFs are finding applications in a variety of fields because of their outstanding chemical and physical properties. This review article focuses on the applications of MOFs in chromatography, including high-performance liquid chromatography (HPLC), gas chromatography (GC), and other chromatographic techniques. The use of MOFs in chromatography has already had a significant impact; however, the utilisation of MOFs in chromatography is still less common than other applications, and the number of MOF materials explored in chromatography applications is limited. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Force-Field Prediction of Materials Properties in Metal-Organic Frameworks

    PubMed Central

    2016-01-01

    In this work, MOF bulk properties are evaluated and compared using several force fields on several well-studied MOFs, including IRMOF-1 (MOF-5), IRMOF-10, HKUST-1, and UiO-66. It is found that, surprisingly, UFF and DREIDING provide good values for the bulk modulus and linear thermal expansion coefficients for these materials, excluding those that they are not parametrized for. Force fields developed specifically for MOFs including UFF4MOF, BTW-FF, and the DWES force field are also found to provide accurate values for these materials’ properties. While we find that each force field offers a moderately good picture of these properties, noticeable deviations can be observed when looking at properties sensitive to framework vibrational modes. This observation is more pronounced upon the introduction of framework charges. PMID:28008758

  17. [Metal-Organic Frameworks: A New Class of Mesoporous Materials and Potential Possibilities of Their Use in Pharmaceutical Technology].

    PubMed

    Wyszogrodzka, Gabriela; Dorożyński, Przemysław

    2015-01-01

    Metal-organic frameworks (MOFs) belong to the new class of mesoporous, hybrid materials composed of metal ions and organic binding ligands. Their unique features: wide range of chemical building components, which enables obtaining biocompatible materials, and high surface area and loading capacity, make them promising drug delivery vehicles for therapeutic agents. The ability to tune their structures and porosities provides better adjustment for adsorbed drug molecule. Moreover, MOFs functionalized with ligands or antibodies can be used in cancer targeted therapy. Through the incorporation of paramagnetic metal ions into the structure, MOFs are suited to serve as magnetic resonance imaging (MRI) contrast agents. Combining drug delivery ability with imaging properties of MOFs indicates their potential use as theranostic agents and makes possible monitoring drug delivery within the body after administration in the real time. The aim of the present study is to characterize a new class of compounds and to present potential possibilities of their use as excipients in pharmaceutical technology .

  18. Post-synthesis modification of a metal-organic framework to form metallosalen-containing MOF materials.

    PubMed

    Shultz, Abraham M; Sarjeant, Amy A; Farha, Omar K; Hupp, Joseph T; Nguyen, SonBinh T

    2011-08-31

    A series of metallosalen-based metal-organic frameworks (MOFs) have been prepared by the post-synthesis modification of Mn(III)SO-MOF, a Mn(3+)(salen)-based MOF. Treatment of Mn(III)SO-MOF with H(2)O(2) effects the removal of the Mn(3+) ions from the salen struts, which can then be remetalated with a variety of metal precursors to form isostructural MSO-MOF materials. The presence of the new metallosalen struts in MSO-MOF was fully confirmed by ICP-OES, MALDI-TOF MS, PXRD, and TGA. Furthermore, the remetalated Mn(II)SO-MOF material displays similar catalytic activity and porosity to the parent MOF.

  19. Dilute NiO/carbon nanofiber composites derived from metal organic framework fibers as electrode materials for supercapacitors

    SciTech Connect

    Yang, Ying; Yang, Feng; Hu, Hongru; Lee, Sungsik; Wang, Yue; Zhao, Hairui; Zeng, Dehong; Zhou, Biao; Hao, Shijie

    2017-01-01

    A new type of carbon nanofiber (CNF) dominated electrode materials decorated with dilute NiO particles (NiO/CNF) has been in situ fabricated by direct pyrolysis of Ni, Zn-containing metal organic framework fibers, which are skillfully constructed by assembling different proportional NiCl2·6H2O and Zn(Ac)2·2H2O with trimesic acid in the presence of N,N-dimethylformamide. With elegant combination of advantages of CNF and evenly dispersed NiO particles, as well as successful modulation of conductivity and porosity of final composites, our NiO/CNF composites display well-defined capacitive features. A high capacitance of 14926 F g–1 was obtained in 6 M KOH electrolyte when the contribution from 0.43 wt% NiO was considered alone, contributing to over 35% of the total capacitance (234 F g–1 ). This significantly exceeds its theoretical specific capacitance of 2584 F g–1. It has been established from the Ragone plot that a largest energy density of 33.4 Wh kg–1 was obtained at the current density of 0.25 A g–1. Furthermore, such composite electrode materials show good rate capability and outstanding cycling stability up to 5000 times (only 10% loss). The present study provides a brand-new approach to design a high capacitance and stable supercapacitor electrode and the concept is extendable to other composite materials. Keywords: Metal organic framework; Nickel oxide; Carbon nanofiber; In situ synthesis; Capacitance

  20. Hydrogen storage in metal-organic frameworks.

    PubMed

    Hu, Yun Hang; Zhang, Lei

    2010-05-25

    Metal-organic frameworks (MOFs) are highly attractive materials because of their ultra-high surface areas, simple preparation approaches, designable structures, and potential applications. In the past several years, MOFs have attracted worldwide attention in the area of hydrogen energy, particularly for hydrogen storage. In this review, the recent progress of hydrogen storage in MOFs is presented. The relationships between hydrogen capacities and structures of MOFs are evaluated, with emphasis on the roles of surface area and pore size. The interaction mechanism between H(2) and MOFs is discussed. The challenges to obtain a high hydrogen capacity at ambient temperature are explored.

  1. Gas separation using novel materials: kinetics of gas adsorption on RPM-1 and Cu-BTC metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Lask, Kathleen; Krungleviciute, Vaiva; Migone, Aldo; Lee, J.-Y.; Li, Jing

    2007-03-01

    We have measured the adsorption kinetics of two gases, freon and argon, on two microporous metal-organic framework materials, RPM-1 (or [Co3(bpdc)3bpy].4DMF.H2O, bpdc = biphenyldicarboxylate) and Cu-BTC (or [Cu3(btc)2(H2O)3], btc = benzenetricarboxylate). The measurements were conducted at comparable values of the scaled temperatures (Tisotherm/Tcritical) for the respective gases. In our experiments, we monitor the pressure decrease as a function of time after a dose of gas is admitted into the experimental cell. The kinetics results obtained for both gases are similar on Cu-BTC, while they are significantly different in RPM-1. Our results indicate that RPM-1 has potential for gas separation for mixtures of species with dimensions similar to argon and freon; this is not the case for Cu-BTC MOF.

  2. Nanoparticle Cookies Derived from Metal-Organic Frameworks: Controlled Synthesis and Application in Anode Materials for Lithium-Ion Batteries.

    PubMed

    Wang, Shuhai; Chen, Minqi; Xie, Yanyu; Fan, Yanan; Wang, Dawei; Jiang, Ji-Jun; Li, Yongguang; Grützmacher, Hansjörg; Su, Cheng-Yong

    2016-05-01

    The capacity of anode materials plays a critical role in the performance of lithium-ion batteries. Using the nanocrystals of oxygen-free metal-organic framework ZIF-67 as precursor, a one-step calcination approach toward the controlled synthesis of CoO nanoparticle cookies with excellent anodic performances is developed in this work. The CoO nanoparticle cookies feature highly porous structure composed of small CoO nanoparticles (≈12 nm in diameter) and nitrogen-rich graphitic carbon matrix (≈18 at% in nitrogen content). Benefiting from such unique structure, the CoO nanoparticle cookies are capable of delivering superior specific capacity and cycling stability (1383 mA h g(-1) after 200 runs at 100 mA g(-1) ) over those of CoO and graphite. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Structural, electronic and elastic properties of several metal organic frameworks as a new kind of energetic materials

    NASA Astrophysics Data System (ADS)

    Zheng, Zhaoyang; Jiang, Xue; Zhao, Jijun

    2015-05-01

    The structural, electronic and elastic properties for metal-organic frameworks (MOFs) as energetic materials are investigated using non-local density functional theory with dispersion correction. The lattice constants of MOF-EMs are reproduced well by optPBE-vdW functional. The electronic structure analysis reveals that NHN is a metal, while the others are semiconductors or insulators with band gap from 0.1 eV to 4.7 eV. NHP, CHP, CHHP and CuAN are predicted to be magnetic. We also discuss the impact sensitivities of MOF-EMs in terms of their electronic structures. The calculated bulk modulus ranges from 15.1 GPa (CuAN) to 35.0 GPa (NHN).

  4. Proton-Conducting Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Ford, Jamie; Simmons, Jason; Yildirim, Taner

    2010-03-01

    Vehicles powered by polymer electrolyte membrane (PEM) fuel cells are an exciting alternative to current fossil fuel technology. The membranes in these cells serve as both charge transporter, ferrying protons from the anode to the cathode, and gas diffusion barrier, preventing the backflow of oxygen to the anode. Currently, hydrated sulfonated polymers are the preferred material for these membranes. The presence of water, however, limits the operating temperature to 100 C, reducing the electrode kinetics and CO tolerance of the entire system. In an effort to increase the efficiency and operating temperature of these fuel cells, we are investigating the proton conductivity of new host/guest materials based on metal-organic frameworks (MOFs) loaded with imidazole. These thermally stable frameworks provide well-defined pores that accommodate imidazole networks and form proton-conducting pathways. Here, we will present the structure and proton dynamics of these materials as elucidated by elastic and inelastic neutron scattering measurements.

  5. Metal-organic framework nanofibers via electrospinning.

    PubMed

    Ostermann, Rainer; Cravillon, Janosch; Weidmann, Christoph; Wiebcke, Michael; Smarsly, Bernd M

    2011-01-07

    A hierarchical system of highly porous nanofibers has been prepared by electrospinning MOF (metal-organic framework) nanoparticles with suitable carrier polymers. Nitrogen adsorption proved the MOF nanoparticles to be fully accessible inside the polymeric fibers.

  6. Evaluation of metal-organic framework 5 as a new SPE material for the determination of polycyclic aromatic hydrocarbons in environmental waters.

    PubMed

    Yang, Shaolei; Chen, Chunyan; Yan, Zhihong; Cai, Qingyun; Yao, Shouzhuo

    2013-04-01

    Metal-organic frameworks, a new class of materials with high surface area and great porosity, have been widely applied in gas sorption. It is generally known that metal-organic framework 5 cannot be applied in aqueous phase since it is water sensitive. However, this work reveals that the derived material of metal-organic framework 5 is a good SPE sorbent that can be applied to aqueous phases. Metal-organic framework 5 was prepared and used as a SPE sorbent for the determination of polycyclic aromatic hydrocarbons in environmental matrices coupling with HPLC. The water treatment induced changes in the properties were investigated in detail. Even though metal-organic framework 5 is conversed to a second phase after water treatment, it still shows high extraction ability. Under the optimized experimental conditions, good sensitivity levels were achieved with low LODs ranging from 0.4 to 4.0 ng L(-1) and a linearity of 0.004-20 μg L(-1) (R(2) > 0.996) for the investigated polycyclic aromatic hydrocarbons. The method has been validated in the analysis of real water samples with recoveries in the range of 80.2-120.2% and RSDs in the range of 0.5-11.7%.

  7. Stimulus-responsive metal-organic frameworks.

    PubMed

    Nagarkar, Sanjog S; Desai, Aamod V; Ghosh, Sujit K

    2014-09-01

    Materials that can recognize the changes in their local environment and respond by altering their inherent physical and/or chemical properties are strong candidates for future "smart" technology materials. Metal-organic frameworks (MOFs) have attracted a great deal of attention in recent years owing to their designable architecture, host-guest chemistry, and softness as porous materials. Despite this fact, studies on the tuning of the properties of MOFs by external stimuli are still rare. This review highlights the recent developments in the field of stimulus-responsive MOFs or so-called smart MOFs. In particular, the various stimuli used and the utility of stimulus-responsive smart MOFs for various applications such as gas storage and separation, sensing, clean energy, catalysis, molecular motors, and biomedical applications are highlighted by using representative examples. Future directions in the developments of stimulus-responsive smart MOFs and their applications are proposed from a personal perspective.

  8. Electrically Conductive Porous Metal-Organic Frameworks.

    PubMed

    Sun, Lei; Campbell, Michael G; Dincă, Mircea

    2016-03-07

    Owing to their outstanding structural, chemical, and functional diversity, metal-organic frameworks (MOFs) have attracted considerable attention over the last two decades in a variety of energy-related applications. Notably missing among these, until recently, were applications that required good charge transport coexisting with porosity and high surface area. Although most MOFs are electrical insulators, several materials in this class have recently demonstrated excellent electrical conductivity and high charge mobility. Herein we review the synthetic and electronic design strategies that have been employed thus far for producing frameworks with permanent porosity and long-range charge transport properties. In addition, key experiments that have been employed to demonstrate electrical transport, as well as selected applications for this subclass of MOFs, will be discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Metal-organic framework nanocrystals as sacrificial templates for hollow and exceptionally porous titania and composite materials.

    PubMed

    Yang, Hui; Kruger, Paul E; Telfer, Shane G

    2015-10-05

    We report a strategy that employs metal-organic framework (MOF) crystals in two roles for the fabrication of hollow nanomaterials. In the first role the MOF crystals provide a template on which a shell of material can be deposited. Etching of the MOF produces a hollow structure with a predetermined size and morphology. In combination with this strategy, the MOF crystals, including guest molecules in their pores, can provide the components of a secondary material that is deposited inside the initially formed shell. We used this approach to develop a straightforward and reproducible method for constructing well-defined, nonspherical hollow and exceptionally porous titania and titania-based composite nanomaterials. Uniform hollow nanostructures of amorphous titania, which assume the cubic or polyhedral shape of the original template, are delivered using nano- and microsized ZIF-8 and ZIF-67 crystal templates. These materials exhibit outstanding textural properties including hierarchical pore structures and BET surface areas of up to 800 m(2)/g. As a proof of principle, we further demonstrate that metal nanoparticles such as Pt nanoparticles, can be encapsulated into the TiO2 shell during the digestion process and used for subsequent heterogeneous catalysis. In addition, we show that the core components of the ZIF nanocrystals, along with their adsorbed guests, can be used as precursors for the formation of secondary materials, following their thermal decomposition, to produce hollow and porous metal sulfide/titania or metal oxide/titania composite nanostructures.

  10. Hydrogen Storage in Metal-Organic Frameworks

    SciTech Connect

    Long, Jeffrey R.

    2016-04-28

    The design and characterization of new materials for hydrogen storage is an important area of research, as the ability to store hydrogen at lower pressures and higher temperatures than currently feasible would lower operating costs for small hydrogen fuel cell vehicles. In particular, metal-organic frameworks (MOFs) represent promising materials for use in storing hydrogen in this capacity. MOFs are highly porous, three-dimensional crystalline solids that are formed via linkages between metal ions (e.g., iron, nickel, and zinc) and organic molecules. MOFs can store hydrogen via strong adsorptive interactions between the gas molecules and the pores of the framework, providing a high surface area for gas adsorption and thus the opportunity to store hydrogen at significantly lower pressures than with current technologies. By lowering the energy required for hydrogen storage, these materials hold promise in rendering hydrogen a more viable fuel for motor vehicles, which is a highly desirable outcome given the clean nature of hydrogen fuel cells (water is the only byproduct of combustion) and the current state of global climate change resulting from the combustion of fossil fuels. The work presented in this report is the result of collaborative efforts between researchers at Lawrence Berkeley National Lab (LBNL), the National Institute of Standards and Technology (NIST), and General Motors Corporation (GM) to discover novel MOFs promising for H2 storage and characterize their properties. Described herein are several new framework systems with improved gravimetric and volumetric capacity to strongly bind H2 at temperatures relevant for vehicle storage. These materials were rigorously characterized using neutron diffraction, to determine the precise binding locations of hydrogen within the frameworks, and high-pressure H2 adsorption measurements, to provide a comprehensive picture of H2 adsorption at all relevant pressures. A

  11. Metal Organic Framework Research: High Throughput Discovery of Robust Metal Organic Framework for CO2 Capture

    SciTech Connect

    2010-08-01

    IMPACCT Project: LBNL is developing a method for identifying the best metal organic frameworks for use in capturing CO2 from the flue gas of coal-fired power plants. Metal organic frameworks are porous, crystalline compounds that, based on their chemical structure, vary considerably in terms of their capacity to grab hold of passing CO2 molecules and their ability to withstand the harsh conditions found in the gas exhaust of coal-fired power plants. Owing primarily to their high tunability, metal organic frameworks can have an incredibly wide range of different chemical and physical properties, so identifying the best to use for CO2 capture and storage can be a difficult task. LBNL uses high-throughput instrumentation to analyze nearly 100 materials at a time, screening them for the characteristics that optimize their ability to selectively adsorb CO2 from coal exhaust. Their work will identify the most promising frameworks and accelerate their large-scale commercial development to benefit further research into reducing the cost of CO2 capture and storage.

  12. Theoretical assessment of the elastic constants and hydrogen storage capacity of some metal-organic framework materials

    NASA Astrophysics Data System (ADS)

    Samanta, Amit; Furuta, Terumi; Li, Ju

    2006-08-01

    Metal-organic frameworks (MOFs) are promising materials for applications such as separation, catalysis, and gas storage. A key indicator of their structural stability is the shear modulus. By density functional theory calculations in a 106-atom supercell, under the local density approximation, we find c11=29.2GPa and c12=13.1GPa for Zn-based MOF 5. However, we find c44 of MOF-5 to be exceedingly small, only 1.4GPa at T =0K. The binding energy Eads of a single hydrogen molecule in MOF-5 is evaluated using the same setup. We find it to be -0.069to-0.086eV/H2 near the benzene linker and -0.106to-0.160eV/H2 near the Zn4O tetrahedra. Substitutions of chlorine and hydroxyl in the benzene linker have negligible effect on the physisorption energies. Pentacoordinated copper (and aluminum) in a framework structure similar to MOF-2 gives Eads≈-0.291eV/H2 (and -0.230eV/H2), and substitution of nitrogen in benzene (pyrazine) further enhances Eads near the organic linker to -0.16eV/H2, according to density functional theory with local density approximation.

  13. Theoretical assessment of the elastic constants and hydrogen storage capacity of some metal-organic framework materials.

    PubMed

    Samanta, Amit; Furuta, Terumi; Li, Ju

    2006-08-28

    Metal-organic frameworks (MOFs) are promising materials for applications such as separation, catalysis, and gas storage. A key indicator of their structural stability is the shear modulus. By density functional theory calculations in a 106-atom supercell, under the local density approximation, we find c(11)=29.2 GPa and c(12)=13.1 GPa for Zn-based MOF 5. However, we find c(44) of MOF-5 to be exceedingly small, only 1.4 GPa at T=0 K. The binding energy E(ads) of a single hydrogen molecule in MOF-5 is evaluated using the same setup. We find it to be -0.069 to -0.086 eVH(2) near the benzene linker and -0.106 to -0.160 eVH(2) near the Zn(4)O tetrahedra. Substitutions of chlorine and hydroxyl in the benzene linker have negligible effect on the physisorption energies. Pentacoordinated copper (and aluminum) in a framework structure similar to MOF-2 gives E(ads) approximately -0.291 eVH(2) (and -0.230 eVH(2)), and substitution of nitrogen in benzene (pyrazine) further enhances E(ads) near the organic linker to -0.16 eVH(2), according to density functional theory with local density approximation.

  14. Nanostructured Electrode Materials Derived from Metal-Organic Framework Xerogels for High-Energy-Density Asymmetric Supercapacitor.

    PubMed

    Mahmood, Asif; Zou, Ruqiang; Wang, Qingfei; Xia, Wei; Tabassum, Hassina; Qiu, Bin; Zhao, Ruo

    2016-01-27

    This work successfully demonstrates metal-organic framework (MOF) derived strategy to prepare nanoporous carbon (NPC) with or without Fe3O4/Fe nanoparticles by the optimization of calcination temperature as highly active electrode materials for asymmetric supercapacitors (ASC). The nanostructured Fe3O4/Fe/C hybrid shows high specific capacitance of 600 F/g at a current density of 1 A/g and excellent capacitance retention up to 500 F/g at 8 A/g. Furthermore, hierarchically NPC with high surface area also obtained from MOF gels displays excellent electrochemical performance of 272 F/g at 2 mV/s. Considering practical applications, aqueous ASC (aASC) was also assembled, which shows high energy density of 17.496 Wh/kg at the power density of 388.8 W/kg. The high energy density and excellent capacity retention of the developed materials show great promise for the practical utilization of these energy storage devices.

  15. Photonic metal-organic framework composite spheres: a new kind of optical material with self-reporting molecular recognition.

    PubMed

    Cui, Jiecheng; Gao, Ning; Wang, Chen; Zhu, Wei; Li, Jian; Wang, Hui; Seidel, Philipp; Ravoo, Bart Jan; Li, Guangtao

    2014-10-21

    Exploiting metal-organic framework (MOF) materials as novel building blocks to construct superstructures with extended and enhanced functions represents a big challenge. In biological systems, the ordering of many components is not achieved by interaction of the components with each other, but by interaction of each component with the host protein which provides a matrix to support the entire assembly. Inspired by biological systems, in this work, a general strategy for efficient spatial arrangement of MOF materials was developed by using spherical colloidal crystals as host matrices, affording a new class of highly tunable MOF composite spheres with a series of distinctive properties. It was found that the synergetic combination of the unique features of both MOF and photonic colloidal crystal imparted these hierarchically structured spheres intrinsic optical properties, specific molecular recognition with self-reporting signalling, derivatization capability, and anisotropy. More importantly, the unique photonic band-gap structure integrated in these composite spheres provides a more convenient means to manipulate the photophysical and photochemical behaviour of the trapped guest molecules in MOF nanocavities.

  16. Cascade reactions catalyzed by metal organic frameworks.

    PubMed

    Dhakshinamoorthy, Amarajothi; Garcia, Hermenegildo

    2014-09-01

    Cascade or tandem reactions where two or more individual reactions are carried out in one pot constitute a clear example of process intensification, targeting the maximization of spatial and temporal productivity with mobilization of minimum resources. In the case of catalytic reactions, cascade processes require bi-/multifunctional catalysts that contain different classes of active sites. Herein, we show that the features and properties of metal-organic frameworks (MOFs) make these solids very appropriate materials for the development of catalysts for cascade reactions. Due to composition and structure, MOFs can incorporate different types of sites at the metal nodes, organic linkers, or at the empty internal pores, allowing the flexible design and synthesis of multifunctional catalysts. After some introductory sections on the relevance of cascade reactions from the point of view of competitiveness, sustainability, and environmental friendliness, the main part of the text provides a comprehensive review of the literature reporting the use of MOFs as heterogeneous catalysts for cascade reactions including those that combine in different ways acid/base, oxidation/reduction, and metal-organic centers. The final section summarizes the current state of the art, indicating that the development of a first commercial synthesis of a high-added-value fine chemical will be a crucial milestone in this area.

  17. An Electrically Switchable Metal-Organic Framework

    NASA Astrophysics Data System (ADS)

    Fernandez, Carlos A.; Martin, Paul C.; Schaef, Todd; Bowden, Mark E.; Thallapally, Praveen K.; Dang, Liem; Xu, Wu; Chen, Xilin; McGrail, B. Peter

    2014-08-01

    Crystalline metal organic framework (MOF) materials containing interconnected porosity can be chemically modified to promote stimulus-driven (light, magnetic or electric fields) structural transformations that can be used in a number of devices. Innovative research strategies are now focused on understanding the role of chemical bond manipulation to reversibly alter the free volume in such structures of critical importance for electro-catalysis, molecular electronics, energy storage technologies, sensor devices and smart membranes. In this letter, we study the mechanism for which an electrically switchable MOF composed of Cu(TCNQ) (TCNQ = 7,7,8,8-tetracyanoquinodimethane) transitions from a high-resistance state to a conducting state in a reversible fashion by an applied potential. The actual mechanism for this reversible electrical switching is still not understood even though a number of reports are available describing the application of electric-field-induced switching of Cu(TCNQ) in device fabrication.

  18. An Electrically Switchable Metal-Organic Framework

    SciTech Connect

    Fernandez, Carlos A.; Martin, Paul F.; Schaef, Herbert T.; Bowden, Mark E.; Thallapally, Praveen K.; Dang, Liem X.; Xu, Wu; Chen, Xilin; McGrail, B. Peter

    2014-08-19

    Crystalline metal organic framework (MOF) materials containing interconnected porosity can be chemically modified to promote stimulus-driven (light, magnetic or electric fields) structural transformations that can be used in a number of devices. Innovative research strategies are now focused on understanding the role of chemical bond manipulation to reversibly alter the free volume in such structures of critical importance for electro-catalysis, molecular electronics, energy storage technologies, sensor devices and smart membranes. In this letter, we study the mechanism for which an electrically switchable MOF composed of Cu(TCNQ) (TCNQ 5 7,7,8,8-tetracyanoquinodimethane) transitions from a high-resistance state to a conducting state in a reversible fashion by an applied potential. The actual mechanism for this reversible electrical switching is still not understood even though a number of reports are available describing the application of electric-field-induced switching of Cu(TCNQ) in device fabrication.

  19. An Electrically Switchable Metal-Organic Framework

    SciTech Connect

    Fernandez, CA; Martin, PC; Schaef, T; Bowden, ME; Thallapally, PK; Dang, L; Xu, W; Chen, XL; McGrail, BP

    2014-08-19

    Crystalline metal organic framework (MOF) materials containing interconnected porosity can be chemically modified to promote stimulus-driven (light, magnetic or electric fields) structural transformations that can be used in a number of devices. Innovative research strategies are now focused on understanding the role of chemical bond manipulation to reversibly alter the free volume in such structures of critical importance for electro-catalysis, molecular electronics, energy storage technologies, sensor devices and smart membranes. In this letter, we study the mechanism for which an electrically switchable MOF composed of Cu(TCNQ) (TCNQ = 7,7,8,8-tetracyanoquinodimethane) transitions from a high-resistance state to a conducting state in a reversible fashion by an applied potential. The actual mechanism for this reversible electrical switching is still not understood even though a number of reports are available describing the application of electric-field-induced switching of Cu(TCNQ) in device fabrication.

  20. An Electrically Switchable Metal-Organic Framework

    PubMed Central

    Fernandez, Carlos A.; Martin, Paul C.; Schaef, Todd; Bowden, Mark E.; Thallapally, Praveen K.; Dang, Liem; Xu, Wu; Chen, Xilin; McGrail, B. Peter

    2014-01-01

    Crystalline metal organic framework (MOF) materials containing interconnected porosity can be chemically modified to promote stimulus-driven (light, magnetic or electric fields) structural transformations that can be used in a number of devices. Innovative research strategies are now focused on understanding the role of chemical bond manipulation to reversibly alter the free volume in such structures of critical importance for electro-catalysis, molecular electronics, energy storage technologies, sensor devices and smart membranes. In this letter, we study the mechanism for which an electrically switchable MOF composed of Cu(TCNQ) (TCNQ = 7,7,8,8-tetracyanoquinodimethane) transitions from a high-resistance state to a conducting state in a reversible fashion by an applied potential. The actual mechanism for this reversible electrical switching is still not understood even though a number of reports are available describing the application of electric-field-induced switching of Cu(TCNQ) in device fabrication. PMID:25135307

  1. Syntheses, structures, tunable emission and white light emitting Eu3+ and Tb3+ doped lanthanide metal-organic framework materials.

    PubMed

    Ma, Ming-Li; Ji, Can; Zang, Shuang-Quan

    2013-08-07

    A series of novel lanthanide metal-organic frameworks, namely, {[Ln2(L)2]·(H2O)3·(Me2NH2)2}n (Ln = La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8), Ho (9), Er (10)), have been synthesized with hydro(solvo)thermal conditions based on a flexible multicarboxylic acid (H4L = 5-(3,5-dicarboxybenzyloxy)isophthalic acid). Single crystal X-ray diffraction reveals that all of them are isomorphous and possess a (6,6) topological net with a Schläfli symbol of {4(8)·6(7)}. Considering the blue-emission of compound 1 and the intense emission of the Eu and Tb compounds, we successfully construct isostructural Eu(3+) doped Tb compounds whose color can be tuned easily by adjusting the different concentration of the doped ions, and we also obtained white light emitting materials through the doping of Eu and Tb ions in the La compounds.

  2. Adsorption of Azo-Dye Orange II from Aqueous Solutions Using a Metal-Organic Framework Material: Iron- Benzenetricarboxylate

    PubMed Central

    Rojas García, Elizabeth; López Medina, Ricardo; May Lozano, Marcos; Hernández Pérez, Isaías; Valero, Maria J.; Maubert Franco, Ana M.

    2014-01-01

    A Metal-Organic Framework (MOF), iron-benzenetricarboxylate (Fe(BTC)), has been studied for the adsorptive removal of azo-dye Orange II from aqueous solutions, where the effect of various parameters was tested and isotherm and kinetic models were suggested. The adsorption capacities of Fe(BTC) were much higher than those of an activated carbon. The experimental data can be best described by the Langmuir isotherm model (R2 > 0.997) and revealed the ability of Fe(BTC) to adsorb 435 mg of Orange II per gram of adsorbent at the optimal conditions. The kinetics of Orange II adsorption followed a pseudo-second-order kinetic model, indicating the coexistence of physisorption and chemisorption, with intra-particle diffusion being the rate controlling step. The thermodynamic study revealed that the adsorption of Orange II was feasible, spontaneous and exothermic process (−25.53 kJ·mol−1). The high recovery of the dye showed that Fe(BTC) can be employed as an effective and reusable adsorbent for the removal of Orange II from aqueous solutions and showed the economic interest of this adsorbent material for environmental purposes. PMID:28788289

  3. Thermodynamics of metal-organic frameworks

    SciTech Connect

    Wu, Di; Navrotsky, Alexandra

    2015-03-15

    Although there have been extensive studies over the past decade in the synthesis and application of metal-organic frameworks (MOFs), investigation of their thermodynamic stability and of the energetics of guest–host interactions has been much more limited. This review summarizes recent progress in experimental (calorimetric) determination of the thermodynamics of MOF materials. The enthalpies of MOFs relative to dense phase assemblages suggest only modest metastability, with a general increase of enthalpy with increasing molar volume, which becomes less pronounced at higher porosity. The energy landscape of nanoporous materials (inorganic and hybrid) consists of a pair of parallel patterns within a fairly narrow range of metastability of 5–30 kJ per mole of tetrahedra in zeolites and mesoporous silicas or per mole of metal in MOFs. Thus strong thermodynamic instability does not seem to limit framework formation. There are strong interactions within the chemisorption range for small molecule–MOF interactions with defined chemical binding at the metal centers or other specific locations. Coexistence of surface binding and confinement can lead to much stronger guest–host interactions. - Graphical abstract: Energy landscape of inorganic and hybrid porous materials. - Highlights: • Thermochemical data on various MOF structures were experimentally determined. • MOFs are moderately unstable relative to their dense phase assemblage. • Overall energetic landscape of porous materials was revealed. • Guest–host interactions in MOFs were evaluated directly using calorimetry. • Confinement effect and defined chemical binding lead to strong interactions.

  4. Smart Optical Composite Materials: Dispersions of Metal-Organic Framework@Superparamagnetic Microrods for Switchable Isotropic-Anisotropic Optical Properties.

    PubMed

    Mandel, Karl; Granath, Tim; Wehner, Tobias; Rey, Marcel; Stracke, Werner; Vogel, Nicolas; Sextl, Gerhard; Müller-Buschbaum, Klaus

    2017-01-24

    A smart optical composite material with dynamic isotropic and anisotropic optical properties by combination of luminescence and high reflectivity was developed. This combination enables switching between luminescence and angle-dependent reflectivity by changing the applied wavelength of light. The composite is formed as anisotropic core/shell particles by coating superparamagnetic iron oxide-silica microrods with a layer of the luminescent metal-organic framework (MOF) (3)∞[Eu2(BDC)3]·2DMF·2H2O (BDC(2-) = 1,4-benzenedicarboxylate). The composite particles can be rotated by an external magnet. Their anisotropic shape causes changes in the reflectivity and diffraction of light depending on the orientation of the composite particle. These rotation-dependent optical properties are complemented by an isotropic luminescence resulting from the MOF shell. If illuminated by UV light, the particles exhibit isotropic luminescence while the same sample shows anisotropic optical properties when illuminated with visible light. In addition to direct switching, the optical properties can be tailored continuously between isotropic red emission and anisotropic reflection of light if the illuminating light is tuned through fractions of both UV and visible light. The integration and control of light emission modes within a homogeneous particle dispersion marks a smart optical material, addressing fundamental directions for research on switchable multifunctional materials. The material can function as an optic compass or could be used as an optic shutter that can be switched by a magnetic field, e.g., for an intensity control for waveguides in the visible range.

  5. Rational Synthesis and Investigation of Porous Metal-Organic Framework Materials from a Preorganized Heterometallic Carboxylate Building Block.

    PubMed

    Sapianik, Aleksandr A; Zorina-Tikhonova, Ekaterina N; Kiskin, Mikhail A; Samsonenko, Denis G; Kovalenko, Konstantin A; Sidorov, Alexey A; Eremenko, Igor L; Dybtsev, Danil N; Blake, Alexander J; Argent, Stephen P; Schröder, Martin; Fedin, Vladimir P

    2017-02-06

    The tetranuclear heterometallic complex [Li2Zn2(piv)6(py)2] (1, where piv(-) = pivalate and py = pyridine) has been successfully employed as a presynthesized node for the construction of four porous metal-organic frameworks (MOFs) [Li2Zn2(R-bdc)3(bpy)]·solv (2-R, R-bdc(2-); R = H, Br, NH2, NO2) by reaction with 4,4'-bipyridine (bpy) and terephthalate anionic linkers. The [Li2Zn2] node is retained in the products, representing a rare example of the rational step-by-step design of isoreticular MOFs based on complex heterometallic building units. The permanent porosity of the activated frameworks was confirmed by gas adsorption isotherm measurements (N2, CO2, CH4). Three compounds, 2-H, 2-Br, and 2-NH2 (but not 2-NO2), feature extensive hysteresis between the adsorption and desorption curves in the N2 isotherms at low pressures. The substituents R decorate the inner surface and also control the aperture of the channels, the volume of the micropores, and the overall surface area, thus affecting both the gas uptake and adsorption selectivity. The highest CO2 absorption at ambient conditions (105 cm(3)·g(-1) or 21 wt % at 273 K and 1 bar for 2-NO2) is above the average values for microporous MOFs. The photoluminescent properties of the prototypic 2-H as well as the corresponding host-guest compounds with various aromatic molecules (benzene, toluene, anisole, and nitrobenzene) were systematically investigated. We discovered a rather complex pattern in the emission response of this material depending on the wavelength of excitation as well as the nature of the guest molecules. On the basis of the crystal structure of 2-H, a mechanism for these luminescent properties is proposed and discussed.

  6. Thermodynamics of metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Wu, Di; Navrotsky, Alexandra

    2015-03-01

    Although there have been extensive studies over the past decade in the synthesis and application of metal-organic frameworks (MOFs), investigation of their thermodynamic stability and of the energetics of guest-host interactions has been much more limited. This review summarizes recent progress in experimental (calorimetric) determination of the thermodynamics of MOF materials. The enthalpies of MOFs relative to dense phase assemblages suggest only modest metastability, with a general increase of enthalpy with increasing molar volume, which becomes less pronounced at higher porosity. The energy landscape of nanoporous materials (inorganic and hybrid) consists of a pair of parallel patterns within a fairly narrow range of metastability of 5-30 kJ per mole of tetrahedra in zeolites and mesoporous silicas or per mole of metal in MOFs. Thus strong thermodynamic instability does not seem to limit framework formation. There are strong interactions within the chemisorption range for small molecule-MOF interactions with defined chemical binding at the metal centers or other specific locations. Coexistence of surface binding and confinement can lead to much stronger guest-host interactions.

  7. Transformation of Metal-Organic Frameworks/Coordination Polymers into Functional Nanostructured Materials: Experimental Approaches Based on Mechanistic Insights.

    PubMed

    Lee, Kyung Joo; Lee, Jae Hwa; Jeoung, Sungeun; Moon, Hoi Ri

    2017-10-09

    Nanostructured materials such as porous metal oxides, metal nanoparticles, porous carbons, and their composites have been intensively studied due to their applications, including energy conversion and storage devices, catalysis, and gas storage. Appropriate precursors and synthetic methods are chosen for synthesizing the target materials. About a decade ago, metal-organic frameworks (MOFs) and coordination polymers (CPs) emerged as new precursors for these nanomaterials because they contain both organic and inorganic species that can play parallel roles as both a template and a precursor under given circumstances. Thermal conversions of MOFs offer a promising toolbox for synthesizing functional nanomaterials that are difficult to obtain using conventional methods. Although understanding the conversion mechanism is important for designing MOF precursors for the synthesis of nanomaterials with desired physicochemical properties, comprehensive discussions revealing the transformation mechanism remain insufficient. This Account reviews the utilization of MOFs/CPs as precursors and their transformation into functional nanomaterials with a special emphasis on understanding the relationship between the intrinsic nature of the parent MOFs and the daughter nanomaterials while discussing various experimental approaches based on mechanistic insights. We discuss nanomaterials categorized by materials such as metal-based nanomaterials and porous carbons. For metal-based nanomaterials transformed from MOFs, the nature of metal ions in the MOF scaffolds affects the physicochemical properties of the resultant materials including the phase, composite, and morphology of nanomaterials. Organic ligands are also involved in the in situ chemical reactions with metal species during thermal conversion. We describe these conversion mechanisms by classifying the phase of metal components in the resultant materials. Along with the metal species, carbon is a major element in MOFs, and thus

  8. Water in Metal-Organic Frameworks: A Computational Study of Adsorption in Porous Materials in the Presence of Ambient Humidity

    NASA Astrophysics Data System (ADS)

    Ghosh, Pritha

    Metal-organic frameworks, or MOFs, are a class of porous crystalline materials renowned for their chemically tunable nature. In this work, molecular-level modeling is used to assess MOFs as potential adsorbents for a variety of applications where ambient humidity is present, such as toxic gas capture, nerve agent decomposition, and sensing via changes in proton conductivity. The concept of hydrophobicity in MOFs is explored from a number of angles. Classical simulation methods and quantum chemistry calculations are used to predict adsorption behavior and to shed light on experimentally observed phenomena. Hydrophobic MOFs are attractive candidates for selective gas capture under ambient conditions, and in this work hydrophobic MOFs are examined for two particular applications: ammonia capture and CO2 capture. In the first study, GCMC simulations are used to evaluate a set of three hydrophobic MOFs for ammonia capture at three humidity conditions: 0% relative humdity (RH), 36% RH, and 80% RH. In the second study, GCMC simulations predict the CO2 loading in a hydrophobic fluorinated MOF at 80% RH, which is the humidity of flue gas. In both of these studies, results demonstrate that hydrophobic MOFs are equally capable of capturing the target adsorbate under humid or dry conditions. In related work, water adsorption behavior is investigated for a fairly hydrophilic Zr MOF, and it is revealed that missing linker defects engender hydrophilicity in this framework. An ideal, defect-free version of this Zr MOF demonstrates hydrophobic behavior. Additionally, perfluoroalkane adsorption is predicted in a related material, a faujasite-type zeolite, and the results suggest the presence of co-adsorbed water molecules. MOFs with coordinated solvent molecules can be used as catalysts and novel chemical sensors. In this work, quantum chemistry calculations are used to study the interaction of a nerve agent simulant with a Zr MOF node. Results indicate that it is favorable for a

  9. Polyoxometalate-Incorporated Metallapillararene/Metallacalixarene Metal-Organic Frameworks as Anode Materials for Lithium Ion Batteries.

    PubMed

    Yang, Xi-Ya; Wei, Tao; Li, Ji-Sen; Sheng, Ning; Zhu, Pei-Pei; Sha, Jing-Quan; Wang, Tong; Lan, Ya-Qian

    2017-07-17

    A series of remarkable crystalline compounds containing metallapillararene/metallacalixarene metal-organic frameworks (MOFs), [Ag5(pyttz)3·Cl·(H2O)][H3SiMo12O40]·3H2O (1), [Ag5(trz)6][H5SiMo12O40] (2), [Ag5(trz)6][H5GeMo12O40] (3), and [Ag5(trz)6][H4PW12O40] (4) (pyttz = 3-(pyrid-4-yl)-5-(1H-1,2,4-triazol-3-yl)-1,2,4-triazolyl, trz = 1,2,4-triazole), have been obtained by using a simple one-step hydrothermal reaction of silver nitrate, pyttz for 1 and trz for 2-4, and Keggin type polyoxometalates (POMs). Crystal analysis reveals that Keggin POMs have been successfully incorporated in the windows of the metallapillararene/metallacalixarene MOFs in compounds 1-4. In addition, the Keggin silicomolybdenate-based hybrid compounds 1 and 2 were used as anode materials in lithium ion batteries (LIBs), which exhibited promising electrochemical performance with the first discharge capacities of 1344 mAh g(-1) for 1 and 1452 mAh g(-1) for 2, and this stabilized at 520 mAh g(-1) for 1 and 570 mAh g(-1) for 2 after 100 cycles at a current density of 100 mA g(-1). The performances are better than that of (NBu4)4[SiMo12O40] matrix and commercial graphite anodes.

  10. (Metal-Organic Framework)-Polyaniline sandwich structure composites as novel hybrid electrode materials for high-performance supercapacitor

    NASA Astrophysics Data System (ADS)

    Guo, ShuaiNan; Zhu, Yong; Yan, YunYun; Min, YuLin; Fan, JinChen; Xu, QunJie; Yun, Hong

    2016-06-01

    Carbonized Zn-(Metal-Organic Framework)MOF- polyaniline composites for high performance of supercapacitor have been developed from zinc acetate, 8-Hydroxyquinoline, and aniline via a simple process. The as-synthesized product has been characterized by X-ray powder diffraction (XRD), Scanning electron microscopy(SEM), Fourier transform infrared spectra (FT-IR), Transmission electron microscope (TEM). The electrochemical properties of carbonized Zn-MOF/polyaniline electrode were investigated by current charge-discharge and cyclic voltammetry. The specific capacitance of MOF/PANI has been approach to be as high as 477 F g-1 at a current density of 1 A g-1.

  11. Microporous Metal Organic Materials for Hydrogen Storage

    SciTech Connect

    S. G. Sankar; Jing Li; Karl Johnson

    2008-11-30

    We have examined a number of Metal Organic Framework Materials for their potential in hydrogen storage applications. Results obtained in this study may, in general, be summarized as follows: (1) We have identified a new family of porous metal organic framework materials with the compositions M (bdc) (ted){sub 0.5}, {l_brace}M = Zn or Co, bdc = biphenyl dicarboxylate and ted = triethylene diamine{r_brace} that adsorb large quantities of hydrogen ({approx}4.6 wt%) at 77 K and a hydrogen pressure of 50 atm. The modeling performed on these materials agree reasonably well with the experimental results. (2) In some instances, such as in Y{sub 2}(sdba){sub 3}, even though the modeling predicted the possibility of hydrogen adsorption (although only small quantities, {approx}1.2 wt%, 77 K, 50 atm. hydrogen), our experiments indicate that the sample does not adsorb any hydrogen. This may be related to the fact that the pores are extremely small or may be attributed to the lack of proper activation process. (3) Some samples such as Zn (tbip) (tbip = 5-tert butyl isophthalate) exhibit hysteresis characteristics in hydrogen sorption between adsorption and desorption runs. Modeling studies on this sample show good agreement with the desorption behavior. It is necessary to conduct additional studies to fully understand this behavior. (4) Molecular simulations have demonstrated the need to enhance the solid-fluid potential of interaction in order to achieve much higher adsorption amounts at room temperature. We speculate that this may be accomplished through incorporation of light transition metals, such as titanium and scandium, into the metal organic framework materials.

  12. Metal-organic framework derived porous CuO/Cu2O composite hollow octahedrons as high performance anode materials for sodium ion batteries.

    PubMed

    Zhang, Xiaojie; Qin, Wei; Li, Dongsheng; Yan, Dong; Hu, Bingwen; Sun, Zhuo; Pan, Likun

    2015-11-25

    Porous CuO/Cu2O composite hollow octahedrons were synthesized simply by annealing Cu-based metal-organic framework templates. When evaluated as anode materials for sodium ion batteries, they exhibit a high maximum reversible capacity of 415 mA h g(-1) after 50 cycles at 50 mA g(-1) with excellent cycling stability and good rate capability.

  13. Ultrahigh porosity in metal-organic frameworks.

    PubMed

    Furukawa, Hiroyasu; Ko, Nakeun; Go, Yong Bok; Aratani, Naoki; Choi, Sang Beom; Choi, Eunwoo; Yazaydin, A Ozgür; Snurr, Randall Q; O'Keeffe, Michael; Kim, Jaheon; Yaghi, Omar M

    2010-07-23

    Crystalline solids with extended non-interpenetrating three-dimensional crystal structures were synthesized that support well-defined pores with internal diameters of up to 48 angstroms. The Zn4O(CO2)6 unit was joined with either one or two kinds of organic link, 4,4',4''-[benzene-1,3,5-triyl-tris(ethyne-2,1-diyl)]tribenzoate (BTE), 4,4',44''-[benzene-1,3,5-triyl-tris(benzene-4,1-diyl)]tribenzoate (BBC), 4,4',44''-benzene-1,3,5-triyl-tribenzoate (BTB)/2,6-naphthalenedicarboxylate (NDC), and BTE/biphenyl-4,4'-dicarboxylate (BPDC), to give four metal-organic frameworks (MOFs), MOF-180, -200, -205, and -210, respectively. Members of this series of MOFs show exceptional porosities and gas (hydrogen, methane, and carbon dioxide) uptake capacities. For example, MOF-210 has Brunauer-Emmett-Teller and Langmuir surface areas of 6240 and 10,400 square meters per gram, respectively, and a total carbon dioxide storage capacity of 2870 milligrams per gram. The volume-specific internal surface area of MOF-210 (2060 square meters per cubic centimeter) is equivalent to the outer surface of nanoparticles (3-nanometer cubes) and near the ultimate adsorption limit for solid materials.

  14. Multifunctional Metal-Organic Frameworks for Photocatalysis.

    PubMed

    Wang, Sibo; Wang, Xinchen

    2015-07-01

    Metal-organic frameworks (MOFs) have attracted significant research attention in diverse areas due to their unique physical and chemical characteristics that allow their innovative application in various research fields. Recently, the application of MOFs in heterogeneous photocatalysis for water splitting, CO2 reduction, and organic transformation have emerged, aiming at providing alternative solutions to address the world-wide energy and environmental problems by taking advantage of the unique porous structure together with ample physicochemical properties of the metal centers and organic ligands in MOFs. In this review, the latest progress in MOF-involved solar-to-chemical energy conversion reactions are summarized according to their different roles in the photoredox chemical systems, e.g., photocatalysts, co-catalysts, and hosts. The achieved progress and existing problems are evaluated and proposed, and the opportunities and challenges of MOFs and their related materials for their advanced development in photocatalysis are discussed and anticipated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Metal-Organic Framework/Chitosan Hybrid Materials Promote Nitric Oxide Release from S-Nitrosoglutathione in Aqueous Solution.

    PubMed

    Neufeld, Megan J; Lutzke, Alec; Tapia, Jesus B; Reynolds, Melissa M

    2017-02-15

    It has been previously demonstrated that copper-based metal-organic frameworks (MOFs) accelerate formation of the therapeutically active molecule nitric oxide (NO) from S-nitrosothiols (RSNOs). Because RSNOs are naturally present in blood, this function is hypothesized to permit the controlled production of NO through use of MOF-based blood-contacting materials. The practical implementation of MOFs in this application typically requires incorporation within a polymer support, yet this immobilization has been shown to impair the ability of the MOF to interact with the NO-forming RSNO substrate. Here, the water-stable, copper-based MOF H3[(Cu4Cl)3-(BTTri)8] (H3BTTri = 1,3,5-tris(1H-1,2,3-triazol-5-yl)benzene), or Cu-BTTri, was incorporated within the naturally derived polysaccharide chitosan to form membranes that were evaluated for their ability to enhance NO generation from the RSNO S-nitrosoglutathione (GSNO). This is the first report to evaluate MOF-induced NO release from GSNO, the most abundant small-molecule RSNO. At a 20 μM initial GSNO concentration (pH 7.4 phosphate buffered saline, 37 °C), chitosan/Cu-BTTri membranes induced the release of 97 ± 3% of theoretical NO within approximately 4 h, corresponding to a 65-fold increase over the baseline thermal decomposition of GSNO. Furthermore, incorporation of Cu-BTTri within hydrophilic chitosan did not impair the activity of the MOF, unlike earlier efforts using hydrophobic polyurethane or poly(vinyl chloride). The reuse of the membranes continued to enhance NO production from GSNO in subsequent experiments, suggesting the potential for continued use. Additionally, the major organic product of Cu-BTTri-promoted GSNO decomposition was identified as oxidized glutathione via mass spectrometry, confirming prior hypotheses. Structural analysis by pXRD and assessment of copper leaching by ICP-AES indicated that Cu-BTTri retains crystallinity and exhibits no significant degradation following exposure to GSNO. Taken

  16. Metal-Organic Frameworks (MOFs) as Multivalent Materials: Size Control and Surface Functionalization by Monovalent Capping Ligands.

    PubMed

    Rijnaarts, Timon; Mejia-Ariza, Raquel; Egberink, Richard J M; van Roosmalen, Wies; Huskens, Jurriaan

    2015-07-13

    Control over particle size and composition are pivotal to tune the properties of metal organic frameworks (MOFs), for example, for biomedical applications. Particle-size control and functionalization of MIL-88A were achieved by using stoichiometric replacement of a small fraction of the divalent fumarate by monovalent capping ligands. A fluorine-capping ligand was used to quantify the surface coverage of capping ligand at the surface of MIL-88A. Size control at the nanoscale was achieved by using a monovalent carboxylic acid-functionalized poly(ethylene glycol) (PEG-COOH) ligand at different concentrations. Finally, a biotin-carboxylic acid capping ligand was used to functionalize MIL-88A to bind fluorescently labeled streptavidin as an example towards bioapplications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Stepwise Synthesis of Metal-Organic Frameworks.

    PubMed

    Bosch, Mathieu; Yuan, Shuai; Rutledge, William; Zhou, Hong-Cai

    2017-03-28

    Metal-organic frameworks (MOFs) are a category of porous materials that offer unparalleled control over their surface areas (demonstrated as higher than for any other material), pore characteristics, and functionalization. This allows them to be customized for exceptional performance in a wide variety of applications, most commonly including gas storage and separation, drug delivery, luminescence, or heterogeneous catalysis. In order to optimize biomimicry, controlled separations and storage of small molecules, and detailed testing of structure-property relationships, one major goal of MOF research is "rational design" or "pore engineering", or precise control of the placement of multiple functional groups in pores of chosen sizes and shapes. MOF crystal growth can be controlled through judicious design of stepwise synthetic routes, which can also allow functionalization of MOFs in ways that were previously synthetically inaccessible. Organic chemists have developed a library of powerful techniques over the last century, allowing the total synthesis and detailed customization of complex molecules. Our hypothesis is that total synthesis is also possible for customized porous materials, through the development of similar multistep techniques. This will enable the rational design of MOFs, which is a major goal of many researchers in the field. We have begun developing a library of stepwise synthetic techniques for MOFs, allowing the synthesis of ultrastable MOFs with multiple crystallographically ordered and customizable functional groups at controlled locations within the pores. In order to design MOFs with precise control over pore size and shape, stability, and the placement of multiple different functional groups within the pores at tunable distances from one another, we have concentrated on methods which allow us to circumvent the lack of control inherent to one-pot MOF crystallization. Kinetically tuned dimensional augmentation (KTDA) is an approach using

  18. Thermodynamics of Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Hughes, James Thomas

    Metal-Organic Frameworks (MOF) are crystalline nanoporous lattices constructed from the combination of cation and multi-dentate organic molecules. MOFs can display both chemical and thermal robustness while having large surface areas and pore volumes. In addition the modular composition of MOFs allows a degree of design and control of MOF structures. These unique physical properties have attracted wide interest and position MOFs to make meaningful contributions towards many applications, such as adsorption, catalysis, separation, and sensing. Despite the extensive investigative work over the last decade on MOF materials, the initial synthesis is still done by trial and error. Of the identified structures some MOFs are robust while others are fragile. It is unclear what role thermodynamics plays in the formation energies of MOFs and guest molecules interactions within the pores. Better understanding of thermochemical properties of MOFs is critical if MOF synthesis is to obtain true predictive design. To address these questions aqueous solution calorimetry was performed on ten different frameworks in both the as-synthesized and activated state. To understand the structural energetics of MOFs, the heat of formation from dense states (metal oxide and protonated organic linkers) to the open MOF framework was measured. Chapter 2 discusses the new aqueous calorimetry methodology developed to measure the enthalpy of solution for hybrid materials. Chapters 3, 4 and 5 detail the enthalpies of formation from their dense states of the frameworks: (MOF-5, ZIF-zni, ZIF-1, ZIF-3, ZIF-4, ZIF-7, ZIF-8, ZIF-9 and Cu-HKUST-1). These chapters also compare the MOF heat of formation energetics to those of zeolites, zeotypes and mesoporous silica materials. Finding that MOFs are metastable with respect to their dense states (metal oxide and protonated organic), following the current destabilization trend of the main group porous materials. The thermochemical effect of solvent on the MOF

  19. Mechanical Alloying of Metal-Organic Frameworks.

    PubMed

    Panda, Tamas; Horike, Satoshi; Hagi, Keisuke; Ogiwara, Naoki; Kadota, Kentaro; Itakura, Tomoya; Tsujimoto, Masahiko; Kitagawa, Susumu

    2017-02-20

    The solvent-free mechanical milling process for two distinct metal-organic framework (MOF) crystals induced the formation of a solid solution, which is not feasible by conventional solution-based syntheses. X-ray and STEM-EDX studies revealed that performing mechanical milling under an Ar atmosphere promotes the high diffusivity of each metal ion in an amorphous solid matrix; the amorphous state turns into the porous crystalline structure by vapor exposure treatment to form a new phase of a MOF solid solution.

  20. Macroscopically Oriented Porous Materials with Periodic Ordered Structures: From Zeolites and Metal-Organic Frameworks to Liquid-Crystal-Templated Mesoporous Materials.

    PubMed

    Cho, Joonil; Ishida, Yasuhiro

    2017-07-01

    Porous materials with molecular-sized periodic structures, as exemplified by zeolites, metal-organic frameworks, or mesoporous silica, have attracted increasing attention due to their range of applications in storage, sensing, separation, and transformation of small molecules. Although the components of such porous materials have a tendency to pack in unidirectionally oriented periodic structures, such ideal types of packing cannot continue indefinitely, generally ceasing when they reach a micrometer scale. Consequently, most porous materials are composed of multiple randomly oriented domains, and overall behave as isotropic materials from a macroscopic viewpoint. However, if their channels could be unidirectionally oriented over a macroscopic scale, the resultant porous materials might serve as powerful tools for manipulating molecules. Guest molecules captured in macroscopically oriented channels would have their positions and directions well-defined, so that molecular events in the channels would proceed in a highly controlled manner. To realize such an ideal situation, numerous efforts have been made to develop various porous materials with macroscopically oriented channels. An overview of recent studies on the synthesis, properties, and applications of macroscopically oriented porous materials is presented. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Immobilization of Bacillus subtilis lipase on a Cu-BTC based hierarchically porous metal-organic framework material: a biocatalyst for esterification.

    PubMed

    Cao, Yu; Wu, Zhuofu; Wang, Tao; Xiao, Yu; Huo, Qisheng; Liu, Yunling

    2016-04-28

    Bacillus subtilis lipase (BSL2) has been successfully immobilized into a Cu-BTC based hierarchically porous metal-organic framework material for the first time. The Cu-BTC hierarchically porous MOF material with large mesopore apertures is prepared conveniently by using a template-free strategy under mild conditions. The immobilized BSL2 presents high enzymatic activity and perfect reusability during the esterification reaction. After 10 cycles, the immobilized BSL2 still exhibits 90.7% of its initial enzymatic activity and 99.6% of its initial conversion.

  2. Hydrogen Storage in Metal-Organic Frameworks

    SciTech Connect

    Omar M. Yaghi

    2012-04-26

    Conventional storage of large amounts of hydrogen in its molecular form is difficult and expensive because it requires employing either extremely high pressure gas or very low temperature liquid. Because of the importance of hydrogen as a fuel, the DOE has set system targets for hydrogen storage of gravimetric (5.5 wt%) and volumetric (40 g L-1) densities to be achieved by 2015. Given that these are system goals, a practical material will need to have higher capacity when the weight of the tank and associated cooling or regeneration system is considered. The size and weight of these components will vary substantially depending on whether the material operates by a chemisorption or physisorption mechanism. In the latter case, metal-organic frameworks (MOFs) have recently been identified as promising adsorbents for hydrogen storage, although little data is available for their sorption behavior. This grant was focused on the study of MOFs with these specific objectives. (1) To examine the effects of functionalization, catenation, and variation of the metal oxide and organic linkers on the low-pressure hydrogen adsorption properties of MOFs. (2) To develop a strategy for producing MOFs with high surface area and porosity to reduce the dead space and increase the hydrogen storage capacity per unit volume. (3) To functionalize MOFs by post synthetic functionalization with metals to improve the adsorption enthalpy of hydrogen for the room temperature hydrogen storage. This effort demonstrated the importance of open metal sites to improve the adsorption enthalpy by the systematic study, and this is also the origin of the new strategy, which termed isoreticular functionalization and metalation. However, a large pore volume is still a prerequisite feature. Based on our principle to design highly porous MOFs, guest-free MOFs with ultrahigh porosity have been experimentally synthesized. MOF-210, whose BET surface area is 6240 m2 g-1 (the highest among porous solids), takes up

  3. Nanoporous carbohydrate metal-organic frameworks.

    PubMed

    Forgan, Ross S; Smaldone, Ronald A; Gassensmith, Jeremiah J; Furukawa, Hiroyasu; Cordes, David B; Li, Qiaowei; Wilmer, Christopher E; Botros, Youssry Y; Snurr, Randall Q; Slawin, Alexandra M Z; Stoddart, J Fraser

    2012-01-11

    The binding of alkali and alkaline earth metal cations by macrocyclic and diazamacrobicyclic polyethers, composed of ordered arrays of hard oxygen (and nitrogen) donor atoms, underpinned the development of host-guest supramolecular chemistry in the 1970s and 1980s. The arrangement of -OCCO- and -OCCN- chelating units in these preorganized receptors, including, but not limited to, crown ethers and cryptands, is responsible for the very high binding constants observed for their complexes with Group IA and IIA cations. The cyclodextrins (CDs), cyclic oligosaccharides derived microbiologically from starch, also display this -OCCO- bidentate motif on both their primary and secondary faces. The self-assembly, in aqueous alcohol, of infinite networks of extended structures, which have been termed CD-MOFs, wherein γ-cyclodextrin (γ-CD) is linked by coordination to Group IA and IIA metal cations to form metal-organic frameworks (MOFs), is reported. CD-MOF-1 and CD-MOF-2, prepared on the gram-scale from KOH and RbOH, respectively, form body-centered cubic arrangements of (γ-CD)(6) cubes linked by eight-coordinate alkali metal cations. These cubic CD-MOFs are (i) stable to the removal of solvents, (ii) permanently porous, with surface areas of ~1200 m(2) g(-1), and (iii) capable of storing gases and small molecules within their pores. The fact that the -OCCO- moieties of γ-CD are not prearranged in a manner conducive to encapsulating single metal cations has led to our isolating other infinite frameworks, with different topologies, from salts of Na(+), Cs(+), and Sr(2+). This lack of preorganization is expressed emphatically in the case of Cs(+), where two polymorphs assemble under identical conditions. CD-MOF-3 has the cubic topology observed for CD-MOFs 1 and 2, while CD-MOF-4 displays a channel structure wherein γ-CD tori are perfectly stacked in one dimension in a manner reminiscent of the structures of some γ-CD solvates, but with added crystal stability imparted

  4. Highly porous metal-organic framework containing a novel organosilicon linker--a promising material for hydrogen storage.

    PubMed

    Wenzel, Stephanie E; Fischer, Michael; Hoffmann, Frank; Fröba, Michael

    2009-07-20

    The synthesis and characterization of the new metal-organic framework PCN-12-Si (isoreticular to PCN-12) is reported. PCN-12-Si comprises dicopper paddle-wheel units located at the vertices of a cuboctahedron, which are connected by the new linker 5,5'-(dimethylsilanediyl)diisophthalate (dmsdip). The microporous MOF has a high specific surface area of S(BET) = 2430 m(2) g(-1) and a high specific micropore volume of V(p) = 0.93 cm(3) g(-1) (p/p(0) = 0.18). The activated form of PCN-12-Si shows a remarkable hydrogen storage capacity. Volumetric low pressure hydrogen physisorption isotherms at 77 K reveal an uptake of 2.6 wt % H(2) at 1 bar. Furthermore, results of theoretical GCMC simulations of hydrogen adsorption are presented. The simulated low pressure isotherm is in excellent agreement with the experimental one. Simulations for the high pressure regime predict an excess hydrogen uptake of 4.8 wt % at 30 bar, which corresponds to an absolute amount adsorbed of 5.5 wt %. In addition, the potential field of H(2) inside PCN-12-Si was derived from the simulations and analyzed in detail, providing valuable insights concerning the preferred adsorption sites on an atomic scale.

  5. A General Model of Sensitized Luminescence in Lanthanide-Based Coordination Polymers and Metal-Organic Framework Materials.

    PubMed

    Einkauf, Jeffrey D; Clark, Jessica M; Paulive, Alec; Tanner, Garrett P; de Lill, Daniel T

    2017-05-15

    Luminescent lanthanides containing coordination polymers and metal-organic frameworks hold great potential in many applications due to their distinctive spectroscopic properties. While the ability to design coordination polymers for specific functions is often mentioned as a major benefit bestowed on these compounds, the lack of a meaningful understanding of the luminescence in lanthanide coordination polymers remains a significant challenge toward functional design. Currently, the study of these compounds is based on the antenna effect as derived from molecular systems, where organic antennae are used to facilitate lanthanide-centered luminescence. This molecular-based approach does not take into account the unique features of extended network solids, particularly the formation of band structure. While guidelines for the antenna effect are well established, they require modification before being applied to coordination polymers. A series of nine coordination polymers with varying topologies and organic linkers were studied to investigate the accuracy of the antenna effect in coordination polymer systems. By comparing a molecular-based approach to a band-based one, it was determined that the band structure that occurs in aggregated organic solids needs to be considered when evaluating the luminescence of lanthanide coordination polymers.

  6. Dynamic interplay between spin-crossover and host-guest function in a nanoporous metal-organic framework material.

    SciTech Connect

    Southon, P. D.; Liu, L.; Fellows, E. A.; Price, D. J.; Halder, G. J.; Chapman, K. W.; Moubaraki, B.; Murray, K. S.; Letard, J.F.; Kepert, C. J.; Univ. Sydney; Monash Univ.; Universite Bordeaux

    2009-01-01

    The nanoporous metal-organic framework [Fe(pz)Ni(CN){sub 4}], 1 (where pz is pyrazine), exhibits hysteretic spin-crossover at ambient conditions and is robust to the adsorption and desorption of a wide range of small molecular guests, both gases (N{sub 2}, O{sub 2}, CO{sub 2}) and vapors (methanol, ethanol, acetone, acetonitrile, and toluene). Through the comprehensive analysis of structure, host-guest properties, and spin-crossover behaviors, it is found that this pillared Hofmann system uniquely displays both guest-exchange-induced changes to spin-crossover and spin-crossover-induced changes to host-guest properties, with direct dynamic interplay between these two phenomena. Guest desorption and adsorption cause pronounced changes to the spin-crossover behavior according to a systematic trend in which larger guests stabilize the high-spin state and therefore depress the spin-crossover temperature of the host lattice. When stabilizing the alternate spin state of the host at any given temperature, these processes directly stimulate the spin-crossover process, providing a chemisensing function. Exploitation of the bistability of the host allows the modification of adsorption properties at a fixed temperature through control of the host spin state, with each state shown to display differing chemical affinities to guest sorption. Guest desorption then adsorption, and vice versa, can be used to switch between spin states in the bistable temperature region, adding a guest-dependent memory effect to this system.

  7. Thermal conversion of an Fe3O4@metal-organic framework: a new method for an efficient Fe-Co/nanoporous carbon microwave absorbing material

    NASA Astrophysics Data System (ADS)

    Zhang, Xingmiao; Ji, Guangbin; Liu, Wei; Quan, Bin; Liang, Xiaohui; Shang, Chaomei; Cheng, Yan; Du, Youwei

    2015-07-01

    A novel FeCo nanoparticle embedded nanoporous carbon composite (Fe-Co/NPC) was synthesized via in situ carbonization of dehydro-ascorbic acid (DHAA) coated Fe3O4 nanoparticles encapsulated in a metal-organic framework (zeolitic imidazolate framework-67, ZIF-67). The molar ratio of Fe/Co significantly depends on the encapsulated content of Fe3O4 in ZIF-67. The composites filled with 50 wt% of the Fe-Co/NPC-2.0 samples in paraffin show a maximum reflection loss (RL) of -21.7 dB at a thickness of 1.2 mm; in addition, a broad absorption bandwidth for RL < -10 dB which covers from 12.2 to 18 GHz can be obtained, and its minimum reflection loss and bandwidth (RL values exceeding -10 dB) are far greater than those of commercial carbonyl iron powder under a very low thickness (1-1.5 mm). This study not only provides a good reference for future preparation of carbon-based lightweight microwave absorbing materials but also broadens the application of such kinds of metal-organic frameworks.A novel FeCo nanoparticle embedded nanoporous carbon composite (Fe-Co/NPC) was synthesized via in situ carbonization of dehydro-ascorbic acid (DHAA) coated Fe3O4 nanoparticles encapsulated in a metal-organic framework (zeolitic imidazolate framework-67, ZIF-67). The molar ratio of Fe/Co significantly depends on the encapsulated content of Fe3O4 in ZIF-67. The composites filled with 50 wt% of the Fe-Co/NPC-2.0 samples in paraffin show a maximum reflection loss (RL) of -21.7 dB at a thickness of 1.2 mm; in addition, a broad absorption bandwidth for RL < -10 dB which covers from 12.2 to 18 GHz can be obtained, and its minimum reflection loss and bandwidth (RL values exceeding -10 dB) are far greater than those of commercial carbonyl iron powder under a very low thickness (1-1.5 mm). This study not only provides a good reference for future preparation of carbon-based lightweight microwave absorbing materials but also broadens the application of such kinds of metal-organic frameworks. Electronic

  8. Nano-architecture of metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Milichko, Valentin A.; Zalogina, Anastasiia; Mingabudinova, Leila R.; Vinogradov, Alexander V.; Ubyivovk, Evgeniy; Krasilin, Andrei A.; Mukhin, Ivan; Zuev, Dmitry A.; Makarov, Sergey V.; Pidko, Evgeny A.

    2017-09-01

    Change the shape and size of materials supports new functionalities never found in the sources. This strategy has been recently applied for porous crystalline materials - metal-organic frameworks (MOFs) to create hollow nanoscale structures or mesostructures with improved functional properties. However, such structures are characterized by amorphous state or polycrystallinity which limits their applicability. Here we follow this strategy to create such nano- and mesostructures with perfect crystallinity and new photonics functionalities by laser or focused ion beam fabrication.

  9. Thermal conversion of an Fe₃O₄@metal-organic framework: a new method for an efficient Fe-Co/nanoporous carbon microwave absorbing material.

    PubMed

    Zhang, Xingmiao; Ji, Guangbin; Liu, Wei; Quan, Bin; Liang, Xiaohui; Shang, Chaomei; Cheng, Yan; Du, Youwei

    2015-08-14

    A novel FeCo nanoparticle embedded nanoporous carbon composite (Fe-Co/NPC) was synthesized via in situ carbonization of dehydro-ascorbic acid (DHAA) coated Fe3O4 nanoparticles encapsulated in a metal-organic framework (zeolitic imidazolate framework-67, ZIF-67). The molar ratio of Fe/Co significantly depends on the encapsulated content of Fe3O4 in ZIF-67. The composites filled with 50 wt% of the Fe-Co/NPC-2.0 samples in paraffin show a maximum reflection loss (RL) of -21.7 dB at a thickness of 1.2 mm; in addition, a broad absorption bandwidth for RL < -10 dB which covers from 12.2 to 18 GHz can be obtained, and its minimum reflection loss and bandwidth (RL values exceeding -10 dB) are far greater than those of commercial carbonyl iron powder under a very low thickness (1-1.5 mm). This study not only provides a good reference for future preparation of carbon-based lightweight microwave absorbing materials but also broadens the application of such kinds of metal-organic frameworks.

  10. A two-fold interpenetrating 3D metal-organic framework material constructed from helical chains linked via 4,4'-H{sub 2}bpz fragments

    SciTech Connect

    Xie Yiming; Zhao Zhenguo; Wu Xiaoyuan; Zhang Qisheng; Chen Lijuan; Wang Fei; Chen Shanci; Lu Canzhong

    2008-12-15

    A 3-connected dia-f-type metal-organic framework compound {l_brace}[Ag(L){sub 3/2}H{sub 2}PO{sub 4}]{r_brace}{sub n} (1) has been synthesized by self-assembly of 4,4'-H{sub 2}bpz (L=4,4'-H{sub 2}bpz=3,3',5,5'-tetramethyl-4,4'-bipyrazole) and Ag{sub 4}P{sub 2}O{sub 7} under hydrothermal conditions. It crystallizes in the tetragonal space group I4{sub 1}/acd with a=21.406(4) A, b=21.406(4) A, c=36.298(8) A, Z=32. X-ray single-crystal diffraction reveals that 1 has a three-dimensional framework with an unprecedented alternate left- and right-handed helices structure, featuring a non-uniform two-fold interpenetrated (4.14{sup 2}) net. Photoluminescent investigation reveals that the title compound displays interesting emissions in a wide region, which shows that the title compound may be a good potential candidate as a photoelectric material. - Graphical abstract: A 3-connected dia-f-type metal-organic framework compound [Ag(4,4'-bpz){sub 3/2}H{sub 2}PO{sub 4}] shows unprecedented alternating left- and right-handed helices structure, featuring a non-uniform two-fold interpenetrated (4.14{sup 2}) net.

  11. Angstrom-Resolved Metal-Organic Framework-Liquid Interfaces.

    PubMed

    Chiodini, Stefano; Reinares-Fisac, Daniel; Espinosa, Francisco M; Gutiérrez-Puebla, Enrique; Monge, Angeles; Gándara, Felipe; Garcia, Ricardo

    2017-09-11

    Metal-organic frameworks (MOFs) are a class of crystalline materials with a variety of applications in gas storage, catalysis, drug delivery or light harvesting. The optimization of those applications requires the characterization of MOF structure in the relevant environment. Dynamic force microscopy has been applied to follow dynamic processes of metal-organic-framework material. We provide images with spatial and time resolutions, respectively, of angstrom and seconds that show that Ce-RPF-8 surfaces immersed in water and glycerol experience a surface reconstruction process that is characterized by the diffusion of the molecular species along the step edges of the open terraces. The rate of the surface reconstruction process depends on the liquid. In water it happens spontaneously while in glycerol is triggered by applying an external force.

  12. Polyoxometalate Cluster-Incorporated Metal-Organic Framework Hierarchical Nanotubes.

    PubMed

    Xu, Xiaobin; Chen, Shuangming; Chen, Yifeng; Sun, Hongyu; Song, Li; He, Wei; Wang, Xun

    2016-06-01

    A simple method to prepare metal-organic framework (MOF) nanotubes is developed by employing polyoxometalates (POMs) as modulators. The local structure of the MOF nanotubes is investigated combining XANES and EXAFS studies. These nanotubes show both an excellent catalytic performance in the detoxification of sulfur compounds in O2 atmosphere and a remarkable cycling stability as the anode material for lithium-ion batteries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Evaluating metal-organic frameworks for natural gas storage

    SciTech Connect

    Mason, JA; Veenstra, M; Long, JR

    2014-01-01

    Metal-organic frameworks have received significant attention as a new class of adsorbents for natural gas storage; however, inconsistencies in reporting high-pressure adsorption data and a lack of comparative studies have made it challenging to evaluate both new and existing materials. Here, we briefly discuss high-pressure adsorption measurements and review efforts to develop metal-organic frameworks with high methane storage capacities. To illustrate the most important properties for evaluating adsorbents for natural gas storage and for designing a next generation of improved materials, six metal-organic frameworks and an activated carbon, with a range of surface areas, pore structures, and surface chemistries representative of the most promising adsorbents for methane storage, are evaluated in detail. High-pressure methane adsorption isotherms are used to compare gravimetric and volumetric capacities, isosteric heats of adsorption, and usable storage capacities. Additionally, the relative importance of increasing volumetric capacity, rather than gravimetric capacity, for extending the driving range of natural gas vehicles is highlighted. Other important systems-level factors, such as thermal management, mechanical properties, and the effects of impurities, are also considered, and potential materials synthesis contributions to improving performance in a complete adsorbed natural gas system are discussed.

  14. Density functional theory meta-GGA + U study of water incorporation in the metal-organic framework material Cu-BTC.

    PubMed

    Cockayne, Eric; Nelson, Eric B

    2015-07-14

    Water absorption in the metal-organic framework (MOF) material Cu-BTC, up to a concentration of 3.5 H2O per Cu ion, is studied via density functional theory at the meta-GGA + U level. The stable arrangements of water molecules show chains of hydrogen-bonded water molecules and a tendency to form closed cages at high concentration. Water clusters are stabilized primarily by a combination of water-water hydrogen bonding and Cu-water oxygen interactions. Stability is further enhanced by van der Waals interactions, electric field enhancement of water-water bonding, and hydrogen bonding of water to framework oxygens. We hypothesize that the tendency to form such stable clusters explains the particularly strong affinity of water to Cu-BTC and related MOFs with exposed metal sites.

  15. Density functional theory meta-GGA + U study of water incorporation in the metal-organic framework material Cu-BTC

    NASA Astrophysics Data System (ADS)

    Cockayne, Eric; Nelson, Eric B.

    2015-07-01

    Water absorption in the metal-organic framework (MOF) material Cu-BTC, up to a concentration of 3.5 H2O per Cu ion, is studied via density functional theory at the meta-GGA + U level. The stable arrangements of water molecules show chains of hydrogen-bonded water molecules and a tendency to form closed cages at high concentration. Water clusters are stabilized primarily by a combination of water-water hydrogen bonding and Cu-water oxygen interactions. Stability is further enhanced by van der Waals interactions, electric field enhancement of water-water bonding, and hydrogen bonding of water to framework oxygens. We hypothesize that the tendency to form such stable clusters explains the particularly strong affinity of water to Cu-BTC and related MOFs with exposed metal sites.

  16. Melt-Quenched Hybrid Glasses from Metal-Organic Frameworks.

    PubMed

    Tao, Haizheng; Bennett, Thomas D; Yue, Yuanzheng

    2017-05-01

    While glasses formed by quenching the molten states of inorganic non-metallic, organic, and metallic species are known, those containing both inorganic and organic moieties are far less prevalent. Network materials consisting of inorganic nodes linked by organic ligands do however exist in the crystalline or amorphous domain. This large family of open framework compounds, called metal-organic frameworks (MOFs) or coordination polymers, has been investigated intensively in the past two decades for a variety of applications, almost all of which stem from their high internal surface areas and chemical versatility. Recently, a selection of MOFs has been demonstrated to undergo melting and vitrification upon cooling. Here, these recent discoveries and the connections between the fields of MOF chemistry and glass science are summarized. Possible advantages and applications for MOF glasses produced by utilizing the tunable chemistry of the crystalline state are also highlighted. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Locating Gases in Porous Materials: Cryogenic Loading of Fuel-Related Gases Into a Sc-based Metal-Organic Framework under Extreme Pressures.

    PubMed

    Sotelo, Jorge; Woodall, Christopher H; Allan, Dave R; Gregoryanz, Eugene; Howie, Ross T; Kamenev, Konstantin V; Probert, Michael R; Wright, Paul A; Moggach, Stephen A

    2015-11-02

    An alternative approach to loading metal organic frameworks with gas molecules at high (kbar) pressures is reported. The technique, which uses liquefied gases as pressure transmitting media within a diamond anvil cell along with a single-crystal of a porous metal-organic framework, is demonstrated to have considerable advantages over other gas-loading methods when investigating host-guest interactions. Specifically, loading the metal-organic framework Sc2BDC3 with liquefied CO2 at 2 kbar reveals the presence of three adsorption sites, one previously unreported, and resolves previous inconsistencies between structural data and adsorption isotherms. A further study with supercritical CH4 at 3-25 kbar demonstrates hyperfilling of the Sc2 BDC3 and two high-pressure displacive and reversible phase transitions are induced as the filled MOF adapts to reduce the volume of the system. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Layer-by-Layer Assembled Films of Perylene Diimide- and Squaraine-Containing Metal-Organic Framework-like Materials: Solar Energy Capture and Directional Energy Transfer.

    PubMed

    Park, Hea Jung; So, Monica C; Gosztola, David; Wiederrecht, Gary P; Emery, Jonathan D; Martinson, Alex B F; Er, Süleyman; Wilmer, Christopher E; Vermeulen, Nicolaas A; Aspuru-Guzik, Alán; Stoddart, J Fraser; Farha, Omar K; Hupp, Joseph T

    2016-09-28

    We demonstrate that thin films of metal-organic framework (MOF)-like materials, containing two perylenediimides (PDICl4, PDIOPh2) and a squaraine dye (S1), can be fabricated by layer-by-layer assembly (LbL). Interestingly, these LbL films absorb across the visible light region (400-750 nm) and facilitate directional energy transfer. Due to the high spectral overlap and oriented transition dipole moments of the donor (PDICl4 and PDIOPh2) and acceptor (S1) components, directional long-range energy transfer from the bluest to reddest absorber was successfully demonstrated in the multicomponent MOF-like films. These findings have significant implications for the development of solar energy conversion devices based on MOFs.

  19. Stable luminescent metal-organic frameworks as dual-functional materials to encapsulate ln(3+) ions for white-light emission and to detect nitroaromatic explosives.

    PubMed

    Xie, Wei; Zhang, Shu-Ran; Du, Dong-Ying; Qin, Jun-Sheng; Bao, Shao-Juan; Li, Jing; Su, Zhong-Min; He, Wen-Wen; Fu, Qiang; Lan, Ya-Qian

    2015-04-06

    A stable porous carbazole-based luminescent metal-organic framework, NENU-522, was successfully constructed. It is extremely stable in air and acidic/basic aqueous solutions, which provides the strategy for luminescent material encapsulation of Ln(3+) ions with tunable luminescence for application in light emission. More importantly, Ln(3+)@NENU-522 can emit white light by encapsulating different molar ratios of Eu(3+) and Tb(3+) ions. Additionally, Tb(3+)@NENU-522 is found to be useful as a fluorescent indicator for the qualitative and quantitative detection of nitroaromatic explosives with different numbers of -NO2 groups, and the concentrations of complete quenching are about 2000, 1000, and 80 ppm for nitrobenzene, 1,3-dinitrobenzene, and 2,4,6-trinitrophenol, respectively. Meanwhile, Tb(3+)@NENU-522 displays high selectivity and recyclability in the detection of nitroaromatic explosives.

  20. De facto methodologies toward the synthesis and scale-up production of UiO-66-type metal-organic frameworks and membrane materials.

    PubMed

    Hu, Zhigang; Zhao, Dan

    2015-11-28

    Metal-organic frameworks (MOFs) are architected via coordination bonds between inorganic metal nodes and organic ligands. They have become emerging advanced porous materials and gained ever-increasing attention in the past decade. In particular, overwhelming studies have been devoted to those hydrostable MOFs which are suggested to be highly promising for industrial applications. UiO-66 is such a unique MOF because of its superior thermal/chemical stability and structural tunability. However, its repeatable, green, and scale-up synthesis remains a challenge for its commercialization and implementation in industrial applications. This perspective mainly summarises the recent development in the synthesis of UiO-66-type MOFs and their related composites. From a scale-up viewpoint, we also present some important advances in the batch and continuous reactor synthesis toward their massive production (226 references).

  1. Water-stable zirconium-based metal-organic framework material with high-surface area and gas-storage capacities.

    PubMed

    Gutov, Oleksii V; Bury, Wojciech; Gomez-Gualdron, Diego A; Krungleviciute, Vaiva; Fairen-Jimenez, David; Mondloch, Joseph E; Sarjeant, Amy A; Al-Juaid, Salih S; Snurr, Randall Q; Hupp, Joseph T; Yildirim, Taner; Farha, Omar K

    2014-09-22

    We designed, synthesized, and characterized a new Zr-based metal-organic framework material, NU-1100, with a pore volume of 1.53 ccg(-1) and Brunauer-Emmett-Teller (BET) surface area of 4020 m(2) g(-1) ; to our knowledge, currently the highest published for Zr-based MOFs. CH4 /CO2 /H2 adsorption isotherms were obtained over a broad range of pressures and temperatures and are in excellent agreement with the computational predictions. The total hydrogen adsorption at 65 bar and 77 K is 0.092 g g(-1) , which corresponds to 43 g L(-1) . The volumetric and gravimetric methane-storage capacities at 65 bar and 298 K are approximately 180 vSTP /v and 0.27 g g(-1) , respectively.

  2. Water-Stable Zirconium-Based Metal-Organic Framework Material with High-Surface Area and Gas-Storage Capacities

    SciTech Connect

    Gutov, OV; Bury, W; Gomez-Gualdron, DA; Krungleviciute, V; Fairen-Jimenez, D; Mondloch, JE; Sarjeant, AA; Al-Juaid, SS; Snurr, RQ; Hupp, JT; Yildirim, T; Farha, OK

    2014-08-14

    We designed, synthesized, and characterized a new Zr-based metal-organic framework material, NU-1100, with a pore volume of 1.53 ccg(-1) and Brunauer-Emmett-Teller (BET) surface area of 4020 m(2)g(-1); to our knowledge, currently the highest published for Zr-based MOFs. CH4/CO2/H-2 adsorption isotherms were obtained over a broad range of pressures and temperatures and are in excellent agreement with the computational predictions. The total hydrogen adsorption at 65 bar and 77 K is 0.092 gg(-1), which corresponds to 43 gL(-1). The volumetric and gravimetric methane-storage capacities at 65 bar and 298 K are approximately 180 v(STP)/v and 0.27 gg(-1), respectively.

  3. Adsorptive removal of methyl orange and methylene blue from aqueous solution with a metal-organic framework material, iron terephthalate (MOF-235).

    PubMed

    Haque, Enamul; Jun, Jong Won; Jhung, Sung Hwa

    2011-01-15

    An iron terephthalate (MOF-235), one of the metal-organic frameworks (MOFs), has been used for the removal of harmful dyes (anionic dye methyl orange (MO) and cationic dye methylene blue (MB)) from contaminated water via adsorption. The adsorption capacities of MOF-235 are much higher than those of an activated carbon. The performance of MOF-235 having high adsorption capacity is remarkable because the MOF-235 does not adsorb nitrogen at liquid nitrogen temperature. Based on this study, MOFs, even if they do not adsorb gases, can be suggested as potential adsorbents to remove harmful materials in the liquid phase. Adsorption of MO and MB at various temperatures shows that the adsorption is a spontaneous and endothermic process and that the entropy increases (the driving force of the adsorption) with adsorption of MO and MB. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Applications of metal-organic frameworks in heterogeneous supramolecular catalysis.

    PubMed

    Liu, Jiewei; Chen, Lianfen; Cui, Hao; Zhang, Jianyong; Zhang, Li; Su, Cheng-Yong

    2014-08-21

    This review summarizes the use of metal-organic frameworks (MOFs) as a versatile supramolecular platform to develop heterogeneous catalysts for a variety of organic reactions, especially for liquid-phase reactions. Following a background introduction about catalytic relevance to various metal-organic materials, crystal engineering of MOFs, characterization and evaluation methods of MOF catalysis, we categorize catalytic MOFs based on the types of active sites, including coordinatively unsaturated metal sites (CUMs), metalloligands, functional organic sites (FOS), as well as metal nanoparticles (MNPs) embedded in the cavities. Throughout the review, we emphasize the incidental or deliberate formation of active sites, the stability, heterogeneity and shape/size selectivity for MOF catalysis. Finally, we briefly introduce their relevance into photo- and biomimetic catalysis, and compare MOFs with other typical porous solids such as zeolites and mesoporous silica with regard to their different attributes, and provide our view on future trends and developments in MOF-based catalysis.

  5. The surface chemistry of metal-organic frameworks.

    PubMed

    McGuire, Christina V; Forgan, Ross S

    2015-03-28

    Metal-organic frameworks (MOFs) have received particular attention over the last 20 years as a result of their attractive properties offering potential applications in a number of areas. Typically, these characteristics are tuned by functionalisation of the bulk of the MOF material itself. This Feature Article focuses instead on modification of MOF particles at their surfaces only, which can also offer control over the bulk properties of the material. The differing surface modification techniques available to the synthetic chemist will be discussed, with a focus on the effect of surface modification of MOFs on their fundamental properties and application in adsorption, catalysis, drug delivery and other areas.

  6. Site characteristics in metal organic frameworks for gas adsorption

    NASA Astrophysics Data System (ADS)

    Uzun, Alper; Keskin, Seda

    2014-02-01

    Metal organic frameworks (MOFs) are a new class of nanoporous materials that have many potential advantages over traditional nanoporous materials for several chemical technologies including gas adsorption, catalysis, membrane-based gas separation, sensing, and biomedical devices. Knowledge on the interaction of guest molecules with the MOF surface is required to design and develop these MOF-based processes. In this review, we examine the importance of identification of gas adsorption sites in MOFs using the current state-of-the-art in experiments and computational modeling. This review provides guidelines to design new MOFs with useful surface properties that exhibit desired performances, such as high gas storage capacity, and high gas selectivity.

  7. Evolution of form in metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Lee, Jiyoung; Kwak, Ja Hun; Choe, Wonyoung

    2017-01-01

    Self-assembly has proven to be a widely successful synthetic strategy for functional materials, especially for metal-organic materials (MOMs), an emerging class of porous materials consisting of metal-organic frameworks (MOFs) and metal-organic polyhedra (MOPs). However, there are areas in MOM synthesis in which such self-assembly has not been fully utilized, such as controlling the interior of MOM crystals. Here we demonstrate sequential self-assembly strategy for synthesizing various forms of MOM crystals, including double-shell hollow MOMs, based on single-crystal to single-crystal transformation from MOP to MOF. Moreover, this synthetic strategy also yields other forms, such as solid, core-shell, double and triple matryoshka, and single-shell hollow MOMs, thereby exhibiting form evolution in MOMs. We anticipate that this synthetic approach might open up a new direction for the development of diverse forms in MOMs, with highly advanced areas such as sequential drug delivery/release and heterogeneous cascade catalysis targeted in the foreseeable future.

  8. Triphenylamine-Based Metal-Organic Frameworks as Cathode Materials in Lithium-Ion Batteries with Coexistence of Redox Active Sites, High Working Voltage, and High Rate Stability.

    PubMed

    Peng, Zhe; Yi, Xiaohui; Liu, Zixuan; Shang, Jie; Wang, Deyu

    2016-06-15

    Through rational organization of two redox active building block, a triphenylamine-based metal-organic framework (MOF) material, Cu-TCA (H3TCA = tricarboxytriphenyl amine), was synthesized and applied as a cathode active material for the first time in lithium batteries. Cu-TCA exhibited redox activity both in the metal clusters (Cu(+)/Cu(2+)) and organic ligand radicals (N/N(+)) with separated voltage plateaus and a high working potential vs Li/Li(+) up to 4.3 V, comparing with the current commercial LiCoO2 cathode materials. The electrochemical behaviors of this MOF electrode material at different states of charge were carefully studied by cyclic voltammetry, X-ray photoelectron spectroscopy, and photoluminescence techniques. Long cycling stability of this MOF was achieved with an average Coulombic efficiency of 96.5% for 200 cycles at a 2 C rate. Discussing the electrochemical performances on the basis of capacity contributions from the metal clusters (Cu(+)/Cu(2+)) and organic ligands (N/N(+)) proposes an alternative mechanism of capacity loss for the MOF materials used in lithium batteries. This improved understanding will shed light on the designing principle of MOF-based cathode materials for their practical application in battery sciences.

  9. Metal-adeninate vertices for the construction of an exceptionally porous metal-organic framework.

    PubMed

    An, Jihyun; Farha, Omar K; Hupp, Joseph T; Pohl, Ehmke; Yeh, Joanne I; Rosi, Nathaniel L

    2012-01-03

    Metal-organic frameworks comprising metal-carboxylate cluster vertices and long, branched organic linkers are the most porous materials known, and therefore have attracted tremendous attention for many applications, including gas storage, separations, catalysis and drug delivery. To increase metal-organic framework porosity, the size and complexity of linkers has increased. Here we present a promising alternative strategy for constructing mesoporous metal-organic frameworks that addresses the size of the vertex rather than the length of the organic linker. This approach uses large metal-biomolecule clusters, in particular zinc-adeninate building units, as vertices to construct bio-MOF-100, an exclusively mesoporous metal-organic framework. Bio-MOF-100 exhibits a high surface area (4,300 m(2) g(-1)), one of the lowest crystal densities (0.302 g cm(-3)) and the largest metal-organic framework pore volume reported to date (4.3 cm(3) g(-1)).

  10. Hierarchical porous anatase TiO2 derived from a titanium metal-organic framework as a superior anode material for lithium ion batteries.

    PubMed

    Xiu, Zhiliang; Alfaruqi, Muhammad Hilmy; Gim, Jihyeon; Song, Jinju; Kim, Sungjin; Vu Thi, Trang; Duong, Pham Tung; Baboo, Joseph Paul; Mathew, Vinod; Kim, Jaekook

    2015-08-07

    Hierarchical meso-/macroporous anatase TiO2 was synthesized by the hydrolysis of a titanium metal-organic framework precursor followed by calcination in air. This unique porous feature enables the superior rate capability and excellent cycling stability of anatase TiO2 as an anode for rechargeable lithium-ion batteries.

  11. Nanostructure and hydrogen spillover of bridged metal-organic frameworks.

    PubMed

    Tsao, Cheng-Si; Yu, Ming-Sheng; Wang, Cheng-Yu; Liao, Pin-Yen; Chen, Hsin-Lung; Jeng, U-Ser; Tzeng, Yi-Ren; Chung, Tsui-Yun; Wu, Hsiu-Chu

    2009-02-04

    The metal-organic frameworks (MOF) with low and medium specific surface areas (SSA) were shown to be able to adsorb hydrogen via bridged spillover at room temperature (RT) up to an amount of full coverage of hydrogen in the MOF. Anomalous small-angle X-ray scattering was employed to investigate the key relationship between the structures and storage properties of the involved materials. It was found that the tunable imperfect lattice defects and the 3D pore network in the MOF crystal are the most critical structures for RT hydrogen uptake rather than the known micropores in the crystal, SSA, and Pt catalyst structure.

  12. Photoresponsive porous materials: the design and synthesis of photochromic diarylethene-based linkers and a metal-organic framework.

    PubMed

    Patel, Dinesh G Dan; Walton, Ian M; Cox, Jordan M; Gleason, Cody J; Butzer, David R; Benedict, Jason B

    2014-03-11

    The synthesis and characterization of novel photochromic diarylethene-based linkers for use in metal–organic frameworks is described including crystal structure analysis of nearly all reaction intermediates. The bis-carboxylated dithien-3-ylphenanthrenes can be prepared under relatively mild conditions in high yield and were subsequently used to create a photoresponsive metal–organic framework, UBMOF-1. While the photochromism of the ligand TPDC in solution is fully reversible, the cycloreversion reaction is suppressed when this linker is incorporated into the crystalline framework of UBMOF-1.

  13. Metal-organic frameworks for Xe/Kr separation

    DOEpatents

    Ryan, Patrick J.; Farha, Omar K.; Broadbelt, Linda J.; Snurr, Randall Q.; Bae, Youn-Sang

    2013-08-27

    Metal-organic framework (MOF) materials are provided and are selectively adsorbent to xenon (Xe) over another noble gas such as krypton (Kr) and/or argon (Ar) as a result of having framework voids (pores) sized to this end. MOF materials having pores that are capable of accommodating a Xe atom but have a small enough pore size to receive no more than one Xe atom are desired to preferentially adsorb Xe over Kr in a multi-component (Xe--Kr mixture) adsorption method. The MOF material has 20% or more, preferably 40% or more, of the total pore volume in a pore size range of 0.45-0.75 nm which can selectively adsorb Xe over Kr in a multi-component Xe--Kr mixture over a pressure range of 0.01 to 1.0 MPa.

  14. Metal-organic frameworks for Xe/Kr separation

    DOEpatents

    Ryan, Patrick J.; Farha, Omar K.; Broadbelt, Linda J.; Snurr, Randall Q.; Bae, Youn-Sang

    2014-07-22

    Metal-organic framework (MOF) materials are provided and are selectively adsorbent to xenon (Xe) over another noble gas such as krypton (Kr) and/or argon (Ar) as a result of having framework voids (pores) sized to this end. MOF materials having pores that are capable of accommodating a Xe atom but have a small enough pore size to receive no more than one Xe atom are desired to preferentially adsorb Xe over Kr in a multi-component (Xe--Kr mixture) adsorption method. The MOF material has 20% or more, preferably 40% or more, of the total pore volume in a pore size range of 0.45-0.75 nm which can selectively adsorb Xe over Kr in a multi-component Xe--Kr mixture over a pressure range of 0.01 to 1.0 MPa.

  15. Metal-organic frameworks with dynamic interlocked components

    NASA Astrophysics Data System (ADS)

    Vukotic, V. Nicholas; Harris, Kristopher J.; Zhu, Kelong; Schurko, Robert W.; Loeb, Stephen J.

    2012-06-01

    The dynamics of mechanically interlocked molecules such as rotaxanes and catenanes have been studied in solution as examples of rudimentary molecular switches and machines, but in this medium, the molecules are randomly dispersed and their motion incoherent. As a strategy for achieving a higher level of molecular organization, we have constructed a metal-organic framework material using a [2]rotaxane as the organic linker and binuclear Cu(II) units as the nodes. Activation of the as-synthesized material creates a void space inside the rigid framework that allows the soft macrocyclic ring of the [2]rotaxane to rotate rapidly, unimpeded by neighbouring molecular components. Variable-temperature 13C and 2H solid-state NMR experiments are used to characterize the nature and rate of the dynamic processes occurring inside this unique material. These results provide a blueprint for the future creation of solid-state molecular switches and molecular machines based on mechanically interlocked molecules.

  16. Stimuli-Responsive Metal Organic Frameworks: Stimuli-Responsive Metal Organic Frameworks for Energy-Efficient Post Combustion Capture

    SciTech Connect

    2010-07-01

    IMPACCT Project: A team led by three professors at Texas A&M is developing a subset of metal organic frameworks that respond to stimuli such as small changes in temperature to trap CO2 and then release it for storage. These frameworks are a promising class of materials for carbon capture applications because their structure and chemistry can be controlled with great precision. Because the changes in temperature required to trap and release CO2 in Texas A&M’s frameworks are much smaller than in other carbon capture approaches, the amount of energy or stimulus that has to be diverted from coal-fired power plants to accomplish this is greatly reduced. The team is working to alter the materials so they bind only with CO2, and are stable enough to withstand the high temperatures found in the chimneys of coal-fired power plants.

  17. From metal-organic framework to intrinsically fluorescent carbon nanodots.

    PubMed

    Amali, Arlin Jose; Hoshino, Hideto; Wu, Chun; Ando, Masanori; Xu, Qiang

    2014-07-01

    Highly photoluminescent carbon nanodots (CNDs) were synthesized for the first time from metal-organic framework (MOF, ZIF-8) nanoparticles. Coupled with fluorescence and non-toxic characteristics, these carbon nanodots could potentially be used in biosafe color patterning.

  18. Coated/Sandwiched rGO/CoSx Composites Derived from Metal-Organic Frameworks/GO as Advanced Anode Materials for Lithium-Ion Batteries.

    PubMed

    Yin, Dongming; Huang, Gang; Zhang, Feifei; Qin, Yuling; Na, Zhaolin; Wu, Yaoming; Wang, Limin

    2016-01-22

    Rational composite materials made from transition metal sulfides and reduced graphene oxide (rGO) are highly desirable for designing high-performance lithium-ion batteries (LIBs). Here, rGO-coated or sandwiched CoSx composites are fabricated through facile thermal sulfurization of metal-organic framework/GO precursors. By scrupulously changing the proportion of Co(2+) and organic ligands and the solvent of the reaction system, we can tune the forms of GO as either a coating or a supporting layer. Upon testing as anode materials for LIBs, the as-prepared CoSx -rGO-CoSx and rGO@CoSx composites demonstrate brilliant electrochemical performances such as high initial specific capacities of 1248 and 1320 mA h g(-1) , respectively, at a current density of 100 mA g(-1) , and stable cycling abilities of 670 and 613 mA h g(-1) , respectively, after 100 charge/discharge cycles, as well as superior rate capabilities. The excellent electrical conductivity and porous structure of the CoSx /rGO composites can promote Li(+) transfer and mitigate internal stress during the charge/discharge process, thus significantly improving the electrochemical performance of electrode materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Metal-organic framework for the separation of alkane isomers

    DOEpatents

    Long, Jeffrey R.; Herm, Zoey R.; Wiers, Brian M.; Krishna, Rajamani

    2017-01-10

    A metal organic framework Fe.sub.2(bdp).sub.3 (BDP.sup.2-=1,4-benzenedipyrazolate) with triangular channels is particularly suited for C5-C7 separations of alkanes according to the number of branches in the molecule rather than by carbon number. The metal-organic framework can offer pore geometries that is unavailable in zeolites or other porous media, facilitating distinct types of shape-based molecular separations.

  20. Biomimicry in metal-organic materials

    SciTech Connect

    Zhang, MW; Gu, ZY; Bosch, M; Perry, Z; Zhou, HC

    2015-06-15

    Nature has evolved a great number of biological molecules which serve as excellent constructional or functional units for metal-organic materials (MOMs). Even though the study of biomimetic MOMs is still at its embryonic stage, considerable progress has been made in the past few years. In this critical review, we will highlight the recent advances in the design, development and application of biomimetic MOMs, and illustrate how the incorporation of biological components into MOMs could further enrich their structural and functional diversity. More importantly, this review will provide a systematic overview of different methods for rational design of MOMs with biomimetic features. Published by Elsevier B.V.

  1. Rapidly assessing the activation conditions and porosity of metal-organic frameworks using thermogravimetric analysis

    SciTech Connect

    McDonald, TM; Bloch, ED; Long, JR

    2015-01-01

    A methodology utilizing a thermogravimetric analyzer to monitor propane uptake following incremental increases of the temperature is demonstrated as a means of rapidly identifying porous materials and determining the optimum activation conditions of metal-organic frameworks.

  2. Near-infrared emitting ytterbium metal-organic frameworks with tunable excitation properties.

    PubMed

    White, Kiley A; Chengelis, Demetra A; Zeller, Matthias; Geib, Steven J; Szakos, Jessica; Petoud, Stéphane; Rosi, Nathaniel L

    2009-08-14

    The design of metal-organic frameworks (MOFs) incorporating near-infrared emitting ytterbium cations and organic sensitizers allows for the preparation of new materials with tunable and enhanced photophysical properties.

  3. Metal-organic framework derived Fe2O3@NiCo2O4 porous nanocages as anode materials for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Huang, Gang; Zhang, Leilei; Zhang, Feifei; Wang, Limin

    2014-04-01

    Metal-organic frameworks (MOFs) with high surface areas and uniform microporous structures have shown potential application in many fields. Here we report a facial strategy to synthesize Fe2O3@NiCo2O4 porous nanocages by annealing core-shell Co3[Fe(CN)6]2@Ni3[Co(CN)6]2 nanocubes in air. The obtained samples have been systematically characterized by XRD, SEM, TEM and N2 adsorption-desorption analysis. The results show that the Fe2O3@NiCo2O4 porous nanocages have an average diameter of 213 nm and a shell thickness of about 30 nm. As anode materials for Li-ion batteries, the Fe2O3@NiCo2O4 porous nanocages exhibit a high initial discharge capacity of 1311.4 mA h g-1 at a current density of 100 mA g-1 (about 0.1 C). The capacity is retained at 1079.6 mA h g-1 after 100 cycles. The synergistic effect of the different components and the porous hollow structure contributes to the outstanding performance of the composite electrode.Metal-organic frameworks (MOFs) with high surface areas and uniform microporous structures have shown potential application in many fields. Here we report a facial strategy to synthesize Fe2O3@NiCo2O4 porous nanocages by annealing core-shell Co3[Fe(CN)6]2@Ni3[Co(CN)6]2 nanocubes in air. The obtained samples have been systematically characterized by XRD, SEM, TEM and N2 adsorption-desorption analysis. The results show that the Fe2O3@NiCo2O4 porous nanocages have an average diameter of 213 nm and a shell thickness of about 30 nm. As anode materials for Li-ion batteries, the Fe2O3@NiCo2O4 porous nanocages exhibit a high initial discharge capacity of 1311.4 mA h g-1 at a current density of 100 mA g-1 (about 0.1 C). The capacity is retained at 1079.6 mA h g-1 after 100 cycles. The synergistic effect of the different components and the porous hollow structure contributes to the outstanding performance of the composite electrode. Electronic supplementary information (ESI) available: Detailed supplementary figures. See DOI: 10.1039/c3nr06041a

  4. A theoretical study of the hydrogen-storage potential of (H2)4CH4 in metal organic framework materials and carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Li, Q.; Thonhauser, T.

    2012-10-01

    The hydrogen-methane compound (H2)4CH4—or for short H4M—is one of the most promising hydrogen-storage materials. This van der Waals compound is extremely rich in molecular hydrogen: 33.3 mass%, not including the hydrogen bound in CH4; including it, we reach even 50.2 mass%. Unfortunately, H4M is not stable under ambient pressure and temperature, requiring either low temperature or high pressure. In this paper, we investigate the properties and structure of the molecular and crystalline forms of H4M, using ab initio methods based on van der Waals DFT (vdW-DF). We further investigate the possibility of creating the pressures required to stabilize H4M through external agents such as metal organic framework (MOF) materials and carbon nanotubes, with very encouraging results. In particular, we find that certain MOFs can create considerable pressure for H4M in their cavities, but not enough to stabilize it at room temperature, and moderate cooling is still necessary. On the other hand, we find that all the investigated carbon nanotubes can create the high pressures required for H4M to be stable at room temperature, with direct implications for new and exciting hydrogen-storage applications.

  5. Metal organic frameworks route to in situ insertion of multiwalled carbon nanotubes in Co3O4 polyhedra as anode materials for lithium-ion batteries.

    PubMed

    Huang, Gang; Zhang, Feifei; Du, Xinchuan; Qin, Yuling; Yin, Dongming; Wang, Limin

    2015-02-24

    Hybridizing nanostructured metal oxides with multiwalled carbon nanotubes (MWCNTs) is highly desirable for the improvement of electrochemical performance of lithium-ion batteries. Here, a facile and scalable strategy to fabricate hierarchical porous MWCNTs/Co3O4 nanocomposites has been reported, with the help of a morphology-maintained annealing treatment of carbon nanotubes inserted metal organic frameworks (MOFs). The designed MWCNTs/Co3O4 integrates the high theoretical capacity of Co3O4 and excellent conductivity as well as strong mechanical/chemical stability of MWCNTs. When tested as anode materials for lithium-ion batteries, the nanocomposite displays a high reversible capacity of 813 mAh g(-1) at a current density of 100 mA g(-1) after 100 charge-discharge cycles. Even at 1000 mA g(-1), a stable capacity as high as 514 mAh g(-1) could be maintained. The improved reversible capacity, excellent cycling stability, and good rate capability of MWCNTs/Co3O4 can be attributed to the hierarchical porous structure and the synergistic effect between Co3O4 and MWCNTs. Furthermore, owing to this versatile strategy, binary metal oxides MWCNTs/ZnCo2O4 could also be synthesized as promising anode materials for advanced lithium-ion batteries.

  6. Post-synthetic structural processing in a metal-organic framework material as a mechanism for exceptional CO2/N2 selectivity.

    PubMed

    Bloch, Witold M; Babarao, Ravichandar; Hill, Matthew R; Doonan, Christian J; Sumby, Christopher J

    2013-07-17

    Here we report the synthesis and ceramic-like processing of a new metal-organic framework (MOF) material, [Cu(bcppm)H2O], that shows exceptionally selective separation for CO2 over N2 (ideal adsorbed solution theory, S(ads) = 590). [Cu(bcppm)H2O]·xS was synthesized in 82% yield by reaction of Cu(NO3)2·2.5H2O with the link bis(4-(4-carboxyphenyl)-1H-pyrazolyl)methane (H2bcppm) and shown to have a two-dimensional 4(4)-connected structure with an eclipsed arrangement of the layers. Activation of [Cu(bcppm)H2O] generates a pore-constricted version of the material through concomitant trellis-type pore narrowing (b-axis expansion and c-axis contraction) and a 2D-to-3D transformation (a-axis contraction) to give the adsorbing form, [Cu(bcppm)H2O]-ac. The pore contraction process and 2D-to-3D transformation were probed by single-crystal and powder X-ray diffraction experiments. The 3D network and shorter hydrogen-bonding contacts do not allow [Cu(bcppm)H2O]-ac to expand under gas loading across the pressure ranges examined or following re-solvation. This exceptional separation performance is associated with a moderate adsorption enthalpy and therefore an expected low energy cost for regeneration.

  7. A theoretical study of the hydrogen-storage potential of (H2)4CH4 in metal organic framework materials and carbon nanotubes.

    PubMed

    Li, Q; Thonhauser, T

    2012-10-24

    The hydrogen-methane compound (H(2))(4)CH(4)-or for short H4M-is one of the most promising hydrogen-storage materials. This van der Waals compound is extremely rich in molecular hydrogen: 33.3 mass%, not including the hydrogen bound in CH(4); including it, we reach even 50.2 mass%. Unfortunately, H4M is not stable under ambient pressure and temperature, requiring either low temperature or high pressure. In this paper, we investigate the properties and structure of the molecular and crystalline forms of H4M, using ab initio methods based on van der Waals DFT (vdW-DF). We further investigate the possibility of creating the pressures required to stabilize H4M through external agents such as metal organic framework (MOF) materials and carbon nanotubes, with very encouraging results. In particular, we find that certain MOFs can create considerable pressure for H4M in their cavities, but not enough to stabilize it at room temperature, and moderate cooling is still necessary. On the other hand, we find that all the investigated carbon nanotubes can create the high pressures required for H4M to be stable at room temperature, with direct implications for new and exciting hydrogen-storage applications.

  8. Carbon-Coated Fe3O4/VOx Hollow Microboxes Derived from Metal-Organic Frameworks as a High-Performance Anode Material for Lithium-Ion Batteries.

    PubMed

    Zhao, Zhi-Wei; Wen, Tao; Liang, Kuang; Jiang, Yi-Fan; Zhou, Xiao; Shen, Cong-Cong; Xu, An-Wu

    2017-02-01

    As the ever-growing demand for high-performance power sources, lithium-ion batteries with high storage capacities and outstanding rate performance have been widely considered as a promising storage device. In this work, starting with metal-organic frameworks, we have developed a facile approach to the synthesis of hybrid Fe3O4/VOx hollow microboxes via the process of hydrolysis and ion exchange and subsequent calcination. In the constructed architecture, the hollow structure provides an efficient lithium ion diffusion pathway and extra space to accommodate the volume expansion during the insertion and extraction of Li(+). With the assistance of carbon coating, the obtained Fe3O4/VOx@C microboxes exhibit excellent cyclability and enhanced rate performance when employed as an anode material for lithium-ion batteries. As a result, the obtained Fe3O4/VOx@C delivers a high Coulombic efficiency (near 100%) and outstanding reversible specific capacity of 742 mAh g(-1) after 400 cycles at a current density of 0.5 A g(-1). Moreover, a remarkable reversible capacity of 556 mAh g(-1) could be retained even at a current density of 2 A g(-1). This study provides a fundamental understanding for the rational design of other composite oxides as high-performance electrode materials for lithium-ion batteries.

  9. High-Performance Energy Storage and Conversion Materials Derived from a Single Metal-Organic Framework/Graphene Aerogel Composite.

    PubMed

    Xia, Wei; Qu, Chong; Liang, Zibin; Zhao, Bote; Dai, Shuge; Qiu, Bin; Jiao, Yang; Zhang, Qiaobao; Huang, Xinyu; Guo, Wenhan; Dang, Dai; Zou, Ruqiang; Xia, Dingguo; Xu, Qiang; Liu, Meilin

    2017-05-10

    Metal oxides and carbon-based materials are the most promising electrode materials for a wide range of low-cost and highly efficient energy storage and conversion devices. Creating unique nanostructures of metal oxides and carbon materials is imperative to the development of a new generation of electrodes with high energy and power density. Here we report our findings in the development of a novel graphene aerogel assisted method for preparation of metal oxide nanoparticles (NPs) derived from bulk MOFs (Co-based MOF, Co(mIM)2 (mIM = 2-methylimidazole). The presence of cobalt oxide (CoOx) hollow NPs with a uniform size of 35 nm monodispersed in N-doped graphene aerogels (NG-A) was confirmed by microscopic analyses. The evolved structure (denoted as CoOx/NG-A) served as a robust Pt-free electrocatalyst with excellent activity for the oxygen reduction reaction (ORR) in an alkaline electrolyte solution. In addition, when Co was removed, the resulting nitrogen-rich porous carbon-graphene composite electrode (denoted as C/NG-A) displayed exceptional capacitance and rate capability in a supercapacitor. Further, this method is readily applicable to creation of functional metal oxide hollow nanoparticles on the surface of other carbon materials such as graphene and carbon nanotubes, providing a good opportunity to tune their physical or chemical activities.

  10. Porous metal-organic frameworks for heterogeneous biomimetic catalysis.

    PubMed

    Zhao, Min; Ou, Sha; Wu, Chuan-De

    2014-04-15

    Metalloporphyrins are the active sites in monooxygenases that oxidize a variety of substrates efficiently and under mild conditions. Researchers have developed artificial metalloporphyrins, but these structures have had limited catalytic applications. Homogeneous artificial metalloporphyrins can undergo catalytic deactivation via suicidal self-oxidation, which lowers their catalytic activity and sustainability relative to their counterparts in Nature. Heme molecules in protein scaffolds can maintain high efficiency over numerous catalytic cycles. Therefore, we wondered if immobilizing metalloporphyrin moieties within porous metal-organic frameworks (MOFs) could stabilize these structures and facilitate the molecular recognition of substrates and produce highly efficient biomimetic catalysis. In this Account, we describe our research to develop multifunctional porphyrinic frameworks as highly efficient heterogeneous biomimetic catalysts. Our studies indicate that porous porphyrinic frameworks provide an excellent platform for mimicking the activity of biocatalysts and developing new heterogeneous catalysts that effect new chemical transformations under mild conditions. The porous structures and framework topologies of the porphyrinic frameworks depend on the configurations, coordination donors, and porphyrin metal ions of the metalloporphyrin moieties. To improve the activity of porous porphyrinic frameworks, we have developed a two-step synthesis that introduces the functional polyoxometalates (POMs) into POM-porphyrin hybrid materials. To tune the pore structures and the catalytic properties of porphyrinic frameworks, we have designed metalloporphyrin M-H8OCPP ligands with four m-benzenedicarboxylate moieties, and introduced the secondary auxiliary ligands. The porphyrin metal ions and the secondary functional moieties that are incorporated into porous metal-organic frameworks greatly influence the catalytic properties and activities of porphyrinic frameworks in

  11. Metal-organic frameworks for membrane-based separations

    NASA Astrophysics Data System (ADS)

    Denny, Michael S.; Moreton, Jessica C.; Benz, Lauren; Cohen, Seth M.

    2016-12-01

    As research into metal-organic frameworks (MOFs) enters its third decade, efforts are naturally shifting from fundamental studies to applications, utilizing the unique features of these materials. Engineered forms of MOFs, such as membranes and films, are being investigated to transform laboratory-synthesized MOF powders to industrially viable products for separations, chemical sensors and catalysts. Following encouraging demonstrations of gas separations using MOF-based membranes, liquid-phase separations are now being explored in an effort to build effective membranes for these settings. In this Review, we highlight MOF applications that are in their nascent stages, specifically liquid-phase separations using MOF-based mixed-matrix membranes. We also highlight the analytical techniques that provide important insights into these materials, particularly at surfaces and interfaces, to better understand MOFs and their interactions with other materials, which will ultimately lead to their use in advanced technologies.

  12. Metal-organic frameworks for lithium ion batteries and supercapacitors

    NASA Astrophysics Data System (ADS)

    Ke, Fu-Sheng; Wu, Yu-Shan; Deng, Hexiang

    2015-03-01

    Porous materials have been widely used in batteries and supercapacitors attribute to their large internal surface area (usually 100-1000 m2 g-1) and porosity that can favor the electrochemical reaction, interfacial charge transport, and provide short diffusion paths for ions. As a new type of porous crystalline materials, metal-organic frameworks (MOFs) have received huge attention in the past decade due to their unique properties, i.e. huge surface area (up to 7000 m2 g-1), high porosity, low density, controllable structure and tunable pore size. A wide range of applications including gas separation, storage, catalysis, and drug delivery benefit from the recent fast development of MOFs. However, their potential in electrochemical energy storage has not been fully revealed. Herein, the present mini review appraises recent and significant development of MOFs and MOF-derived materials for rechargeable lithium ion batteries and supercapacitors, to give a glimpse into these potential applications of MOFs.

  13. Screening metal-organic frameworks for separation of pentane isomers.

    PubMed

    Krishna, Rajamani; van Baten, Jasper M

    2017-03-28

    This article compares the performances of several metal-organic frameworks (MOFs) and zeolitic imidazolate frameworks (ZIFs) for the separation of pentane isomers: n-pentane (nC5), 2-methylbutane (2MB), and 2,2-dimethylpropane (= neo-pentane (neo-P)) in fixed bed adsorbers. The required input data on unary and mixture adsorption equilibria are obtained from Configurational-Bias Monte Carlo (CBMC) simulations for twelve different adsorbents. The best separation performance is realized with Fe2(BDP)3, where BDP(2-) = 1,4-benzenedipyrazolate, a MOF with triangular shaped 4.9 Å channels that affords the ideal pore topology to differentiate between the three pentane isomers; the linear nC5 aligns commensurately with the pore landscape. Using transient breakthrough simulations in fixed bed adsorbers, the separation performance of Fe2(BDP)3 is found to be significantly superior to that of other materials.

  14. Efficient and Selective Uptake of TcO4(-) by a Cationic Metal-Organic Framework Material with Open Ag(+) Sites.

    PubMed

    Sheng, Daopeng; Zhu, Lin; Xu, Chao; Xiao, Chengliang; Wang, Yanlong; Wang, Yaxing; Chen, Lanhua; Diwu, Juan; Chen, Jing; Chai, Zhifang; Albrecht-Schmitt, Thomas E; Wang, Shuao

    2017-03-21

    (99)Tc is one of the most problematic radioisotopes in used nuclear fuel owing to its combined features of high fission yield, long half-life, and high environmental mobility. There are only a handful of functional materials that can remove TcO4(-) anion from aqueous solution and identifying for new, stable materials with high anion-exchange capacities, fast kinetics, and good selectivity remains a challenge. We report here an 8-fold interpenetrated three-dimensional cationic metal-organic framework material, SCU-100, which is assembled from a tetradentate neutral nitrogen-donor ligand and two-coordinate Ag(+) cations as potential open metal sites. The structure also contains a series of 1D channels filled with unbound nitrate anions. SCU-100 maintains its crystallinity in aqueous solution over a wide pH range from 1 to 13 and exhibits excellent β and γ radiation-resistance. Initial anion exchange studies show that SCU-100 is able to both quantitatively and rapidly remove TcO4(-) from water within 30 min. The exchange capacity for the surrogate ReO4(-) reaches up to 541 mg/g and the distribution coefficient Kd is up to 1.9 × 10(5) mL/g, which are significantly higher than all previously tested inorganic anion sorbent materials. More importantly, SCU-100 can selectively capture TcO4(-) in the presence of large excess of competitive anions (NO3(-), SO4(2-), CO3(2-), and PO4(3-)) and remove as much as 87% of TcO4(-) from the Hanford low-level waste melter off-gas scrubber simulant stream within 2 h. The sorption mechanism is well elucidated by single crystal X-ray diffraction, showing that the sorbed ReO4(-) anion is able to selectively coordinate to the open Ag(+) sites forming Ag-O-Re bonds and a series of hydrogen bonds. This further leads to a single-crystal-to-single-crystal transformation from an 8-fold interpenetrated framework with disordered nitrate anions to a 4-fold interpenetrated framework with fully ordered ReO4(-) anions. This work represents a

  15. Co3V2O8 Sponge Network Morphology Derived from Metal-Organic Framework as an Excellent Lithium Storage Anode Material.

    PubMed

    Soundharrajan, Vaiyapuri; Sambandam, Balaji; Song, Jinju; Kim, Sungjin; Jo, Jeonggeun; Kim, Seokhun; Lee, Seulgi; Mathew, Vinod; Kim, Jaekook

    2016-04-06

    Metal-organic framework (MOF)-based synthesis of battery electrodes has presntly become a topic of significant research interest. Considering the complications to prepare Co3V2O8 due to the criticality of its stoichiometric composition, we report on a simple MOF-based solvothermal synthesis of Co3V2O8 for use as potential anodes for lithium battery applications. Characterizations by X-ray diffraction, X-ray photoelectron spectroscopy, high resolution electron microscopy, and porous studies revealed that the phase pure Co3V2O8 nanoparticles are interconnected to form a sponge-like morphology with porous properties. Electrochemical measurements exposed the excellent lithium storage (∼1000 mAh g(-1) at 200 mA g(-1)) and retention properties (501 mAh g(-1) at 1000 mA g(-1) after 700 cycles) of the prepared Co3V2O8 electrode. A notable rate performance of 430 mAh g(-1) at 3200 mA g(-1) was also observed, and ex situ investigations confirmed the morphological and structural stability of this material. These results validate that the unique nanostructured morphology arising from the use of the ordered array of MOF networks is favorable for improving the cyclability and rate capability in battery electrodes. The synthetic strategy presented herein may provide solutions to develop phase pure mixed metal oxides for high-performance electrodes for useful energy storage applications.

  16. In-situ Fabrication of Graphene Oxide Hybrid Ni-based Metal-Organic Framework (Ni-MOFs@GO) with Ultrahigh Capacitance as Electrochemical Pseudocapacitor Materials.

    PubMed

    Zhou, Yingjie; Mao, Zemin; Wang, Wei; Yang, Zhengkai; Liu, Xiang

    2016-10-03

    This paper reports a series of novel Ni-based metal-organic framework (Ni-MOFs) prepared by a facile solvothermal process. The synthetic conditions have great effects on the Ni-MOFs morphologies, porous textures and their electrochemical performances. Improved capacitance performance was successfully realized by the in-situ hybrid of Ni-MOFs with graphene oxide (GO) nanosheets (Ni-MOFs@GO). The pseudocapacitance ca. 1457.7 F/g for Ni-MOFs obtained at 180 ºC with HCl as the modulator was elevated to ca. 2192.4 F/g at the current density of 1 A/g for the Ni-MOFs@GO with the GO contents of 3 wt%. Additionally, the capacitance retention was also promoted from ca. 83.5% to 85.1% of its original capacitance at 10 A/g even after 3000 cycles accordingly. These outstanding electrochemical properties of Ni-based MOF materials may be related to their inherent characteristics, such as the unique flower-like architecture, fascinating synergetic effect between the Ni-MOFs and the GO nanosheets.

  17. Metal-organic framework derived Fe2O3@NiCo2O4 porous nanocages as anode materials for Li-ion batteries.

    PubMed

    Huang, Gang; Zhang, Leilei; Zhang, Feifei; Wang, Limin

    2014-05-21

    Metal-organic frameworks (MOFs) with high surface areas and uniform microporous structures have shown potential application in many fields. Here we report a facial strategy to synthesize Fe2O3@NiCo2O4 porous nanocages by annealing core-shell Co3[Fe(CN)6]2@Ni3[Co(CN)6]2 nanocubes in air. The obtained samples have been systematically characterized by XRD, SEM, TEM and N2 adsorption-desorption analysis. The results show that the Fe2O3@NiCo2O4 porous nanocages have an average diameter of 213 nm and a shell thickness of about 30 nm. As anode materials for Li-ion batteries, the Fe2O3@NiCo2O4 porous nanocages exhibit a high initial discharge capacity of 1311.4 mA h g(-1) at a current density of 100 mA g(-1) (about 0.1 C). The capacity is retained at 1079.6 mA h g(-1) after 100 cycles. The synergistic effect of the different components and the porous hollow structure contributes to the outstanding performance of the composite electrode.

  18. Chitosan capped nanoscale Fe-MIL-88B-NH2 metal-organic framework as drug carrier material for the pH responsive delivery of doxorubicin

    NASA Astrophysics Data System (ADS)

    Sivakumar, P.; Priyatharshni, S.; Nagashanmugam, K. B.; Thanigaivelan, A.; Kumar, K.

    2017-08-01

    In recent years nanoscale metal-organic frameworks (NMOFs) are contributing as an effective material for use in drug delivery and imaging applications due to their porous surfaces and easy surface modifications. In this work, Fe-MIL-88B-NH2 NMOFs were successfully synthesized on facile hydrothermal route and 2-aminoterephthalic acid (NH2-BDC) was employed as a bridging ligand to activate amine functional groups on the surface. Amine functional groups not only serve as a structure stabilizing agent but also enhance the loading efficiency of the doxorubicin (DOX) anticancer drug. A pH responsive DOX release was realized by introducing a positively charged chitosan (Chi) capping layer. Upon Chi-coating, cleavage was observed in the Fe-MIL-88B-NH2 structure at acidic pH, while gel-like insoluble structure was formed at basic pH. By utilizing this phenomenon, a pH responsive DOX release system was developed by using Chi capped Fe-MIL-88B-NH2 NMOFs under the designed pH (4.0-8.0). The results suggest the Chi capped Fe-MIL-88B-NH2 can be a promising candidate for future pH responsive drug delivery systems.

  19. High methane storage capacity in aluminum metal-organic frameworks.

    PubMed

    Gándara, Felipe; Furukawa, Hiroyasu; Lee, Seungkyu; Yaghi, Omar M

    2014-04-09

    The use of porous materials to store natural gas in vehicles requires large amounts of methane per unit of volume. Here we report the synthesis, crystal structure and methane adsorption properties of two new aluminum metal-organic frameworks, MOF-519 and MOF-520. Both materials exhibit permanent porosity and high methane volumetric storage capacity: MOF-519 has a volumetric capacity of 200 and 279 cm(3) cm(-3) at 298 K and 35 and 80 bar, respectively, and MOF-520 has a volumetric capacity of 162 and 231 cm(3) cm(-3) under the same conditions. Furthermore, MOF-519 exhibits an exceptional working capacity, being able to deliver a large amount of methane at pressures between 5 and 35 bar, 151 cm(3) cm(-3), and between 5 and 80 bar, 230 cm(3) cm(-3).

  20. Multi-Photon Absorption in Metal-Organic Frameworks.

    PubMed

    Medishetty, Raghavender; Nemec, Lydia; Nalla, Venkatram; Henke, Sebastian; Samoc, Marek; Reuter, Karsten; Fischer, Roland A

    2017-09-12

    Multi-photon absorption (MPA) is among the most prominent nonlinear optical (NLO) effects and has applications, for example in telecommunications, defense, photonics and bio-medicines. Established MPA materials include dyes, quantum dots, organometallics and conjugated polymers, most often dispersed in solution. We demonstrate how metal-organic frameworks (MOFs), a novel NLO solid-state materials class, can be designed for exceptionally strong MPA behavior. MOFs consisting of zirconium- and hafnium-oxo-clusters and featuring a chromophore linker based on the tetraphenylethene (TPE) molecule exhibit record high two-photon absorption (2PA) cross section values, up to 3600 GM. The unique modular building-block principle of MOFs allows enhancing and optimizing their MPA properties in a theory guided approach by combining tailored charge polarization, conformational strain, three-dimensional arrangement and alignment of the chromophore linkers in the crystal. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Ligand design for functional metal-organic frameworks.

    PubMed

    Paz, Filipe A Almeida; Klinowski, Jacek; Vilela, Sérgio M F; Tomé, João P C; Cavaleiro, José A S; Rocha, João

    2012-02-07

    Metal-organic frameworks (MOFs), also known as coordination polymers, are formed by the self-assembly of metallic centres and bridging organic linkers. In this critical review, we review the key advances in the field and discuss the relationship between the nature and structure of specifically designed organic linkers and the properties of the products. Practical examples demonstrate that the physical and chemical properties of the linkers play a decisive role in the properties of novel functional MOFs. We focus on target materials suitable for the storage of hydrogen and methane, sequestration of carbon dioxide, gas separation, heterogeneous catalysis and as magnetic and photoluminescent materials capable of both metal- and ligand-centred emission, ion exchangers and molecular sieves. The advantages of highly active discrete complexes as metal-bearing ligands in the construction of MOFs are also briefly reviewed (128 references). This journal is © The Royal Society of Chemistry 2012

  2. Iodine confinement into metal-organic frameworks (MOFs)-low temperature sintering glasses to form novel glass composite material (GCM) alternative waste forms.

    SciTech Connect

    Nenoff, Tina Maria; Garino, Terry J.; Sava, Dorina Florentina

    2010-11-01

    The safe handling of reprocessed fuel addresses several scientific goals, especially when considering the capture and long-term storage of volatile radionuclides that are necessary during this process. Despite not being a major component of the off-gas, radioiodine (I{sub 2}) is particularly challenging, because it is a highly mobile gas and {sup 129}I is a long-lived radionuclide (1.57 x 10{sup 7} years). Therefore, its capture and sequestration is of great interest on a societal level. Herein, we explore novel routes toward the effective capture and storage of iodine. In particular, we report on the novel use of a new class of porous solid-state functional materials (metal-organic frameworks, MOFs), as high-capacity adsorbents of molecular iodine. We further describe the formation of novel glass-composite material (GCM) waste forms from the mixing and sintering of the I{sub 2}-containing MOFs with Bi-Zn-O low-temperature sintering glasses and silver metal flakes. Our findings indicate that, upon sintering, a uniform monolith is formed, with no evidence of iodine loss; iodine is sequestered during the heating process by the in situ formation of AgI. Detailed materials characterization analysis is presented for the GCMs. This includes powder X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), thermal analysis (thermogravimetric analysis (TGA)), and chemical durability tests including aqueous leach studies (product consistency test (PCT)), with X-ray fluorescence (XRF) and inductively coupled plasma-mass spectrometry (ICP-MS) of the PCT leachate.

  3. Hierarchically Flower-like N-Doped Porous Carbon Materials Derived from an Explosive 3-Fold Interpenetrating Diamondoid Copper Metal-Organic Framework for a Supercapacitor.

    PubMed

    Li, Zuo-Xi; Zou, Kang-Yu; Zhang, Xue; Han, Tong; Yang, Ying

    2016-07-05

    A peculiar copper metal-organic framework (Cu-MOF) was synthesized by a self-assembly method, which presents a 3-fold interpenetrating diamondoid net based on the square-planar Cu(II) node. Although it exhibits a high degree of interpenetration, the Cu-MOF still exhibits a one-dimensional channel, which provides a template for constructing porous materials through the "precursor" strategy. Furthermore, the explosive ClO4(-) ion, which resided in the channel, could induce the quick decomposition of organic ingredients and release a huge amount of gas, which is beneficial for the porosity of postsynthetic materials. Significantly, we first utilize this explosive MOF to prepare a series of Cu@C composites through the calcination-thermolysis method at different temperatures, which contain copper particles exhibiting various shapes and combinations with the carbon substrate. Considering the hole-forming effect of copper particles, Cu@C composites were etched by HCl to afford a sequence of hierarchically flower-like N-doped porous carbon materials (NPCs), which retain the original morphology of the Cu-MOF. Interestingly, NPC-900, originating from the calcination of the Cu-MOF at 900 °C, exhibits a more regular flower-like morphology, the largest specific surface area, abundant porosities, and multiple nitrogen functionalities. The remarkable specific capacitances are 138 F g(-1) at 5 mV s(-1) and 149 F g(-1) at 0.5 A g(-1) for the NPC-900 electrode in a 6 M potassium hydroxide aqueous solution. Moreover, the retention of capacitance remains 86.8% (125 F g(-1)) at 1 A g(-1) over 2000 cycles, which displays good chemical stability. These findings suggest that NPC-900 can be applied as a suitable electrode for a supercapacitor.

  4. Selective anion exchange with nanogated isoreticular positive metal-organic frameworks.

    PubMed

    Zhao, Xiang; Bu, Xianhui; Wu, Tao; Zheng, Shou-Tian; Wang, Le; Feng, Pingyun

    2013-01-01

    Crystalline porous materials, especially inorganic porous solids such as zeolites, usually have negative frameworks with extra-framework mobile cations and are widely used for cation exchange. It is highly desirable to develop new materials with positive frameworks for selective anion exchange and separation or storage and delivery. Recent advances in metal-organic framework synthesis have created new opportunities in this direction. Here we report the synthesis of a series of positive indium metal-organic frameworks and their utilization as a platform for the anion exchange-based separation process. This process is capable of size- or charge-selective ion-exchange of organic dyes and may form the basis for size-selective ion chromatography. Ion-exchange dynamics of a series of organic dyes and their selective encapsulation and release are also studied, highlighting the advantages of metal-organic framework compositions for designing host materials tailored for applications in anion separation and purification.

  5. Synthesis of Hierarchically Structured Hybrid Materials by Controlled Self-Assembly of Metal-Organic Framework with Mesoporous Silica for CO2 Adsorption.

    PubMed

    Chen, Chong; Li, Bingxue; Zhou, Lijin; Xia, Zefeng; Feng, Nengjie; Ding, Jing; Wang, Lei; Wan, Hui; Guan, Guofeng

    2017-07-12

    The HKUST-1@SBA-15 composites with hierarchical pore structure were constructed by in situ self-assembly of metal-organic framework (MOF) with mesoporous silica. The structure directing role of SBA-15 had an obvious impact on the growth of MOF crystals, which in turn affected the morphologies and structural properties of the composites. The pristine HKUST-1 and the composites with different content of SBA-15 were characterized by XRD, N2 adsorption-desorption, SEM, TEM, FT-IR, TG, XPS, and CO2-TPD techniques. It was found that the composites were assembled by oriented growth of MOF nanocrystals on the surfaces of SBA-15 matrix. The interactions between surface silanol groups and metal centers induced structural changes and resulted in the increases in surface areas as well as micropore volumes of hybrid materials. Besides, the additional constraints from SBA-15 also restrained the expansion of HKUST-1, contributing to their smaller crystal sizes in the composites. The adsorption isotherms of CO2 on the materials were measured and applied to calculate the isosteric heats of adsorption. The HS-1 composite exhibited an increase of 15.9% in CO2 uptake capacity compared with that of HKUST-1. Moreover, its higher isosteric heats of CO2 adsorption indicated the stronger interactions between the surfaces and CO2 molecules. The adsorption rate of the composite was also improved due to the introduction of mesopores. Ten cycles of CO2 adsorption-desorption experiments implied that the HS-1 had excellent reversibility of CO2 adsorption. This study was intended to provide the possibility of assembling new composites with tailored properties based on MOF and mesoporous silica to satisfy the requirements of various applications.

  6. Increasing the Stability of Metal-Organic Frameworks

    DOE PAGES

    Bosch, Mathieu; Zhang, Muwei; Zhou, Hong-Cai

    2014-01-01

    Metal-organic frameworks (MOFs) are a new category of advanced porous materials undergoing study by many researchers for their vast variety of both novel structures and potentially useful properties arising from them. Their high porosities, tunable structures, and convenient process of introducing both customizable functional groups and unsaturated metal centers have afforded excellent gas sorption and separation ability, catalytic activity, luminescent properties, and more. However, the robustness and reactivity of a given framework are largely dependent on its metal-ligand interactions, where the metal-containing clusters are often vulnerable to ligand substitution by water or other nucleophiles, meaning that the frameworks may collapsemore » upon exposure even to moist air. Other frameworks may collapse upon thermal or vacuum treatment or simply over time. This instability limits the practical uses of many MOFs. In order to further enhance the stability of the framework, many different approaches, such as the utilization of high-valence metal ions or nitrogen-donor ligands, were recently investigated. This review details the efforts of both our research group and others to synthesize MOFs possessing drastically increased chemical and thermal stability, in addition to exemplary performance for catalysis, gas sorption, and separation.« less

  7. Correlated defect nanoregions in a metal-organic framework

    NASA Astrophysics Data System (ADS)

    Cliffe, Matthew J.; Wan, Wei; Zou, Xiaodong; Chater, Philip A.; Kleppe, Annette K.; Tucker, Matthew G.; Wilhelm, Heribert; Funnell, Nicholas P.; Coudert, François-Xavier; Goodwin, Andrew L.

    2014-06-01

    Throughout much of condensed matter science, correlated disorder is a key to material function. While structural and compositional defects are known to exist within a variety of metal-organic frameworks (MOFs), the prevailing understanding is that these defects are only ever included in a random manner. Here we show—using a combination of diffuse scattering, electron microscopy, anomalous X-ray scattering and pair distribution function measurements—that correlations between defects can in fact be introduced and controlled within a hafnium terephthalate MOF. The nanoscale defect structures that emerge are an analogue of correlated Schottky vacancies in rocksalt-structured transition metal monoxides and have implications for storage, transport, optical and mechanical responses. Our results suggest how the diffraction behaviour of some MOFs might be reinterpreted, and establish a strategy of exploiting correlated nanoscale disorder as a targetable and desirable motif in MOF design.

  8. "Heterogeneity within order" in metal-organic frameworks.

    PubMed

    Furukawa, Hiroyasu; Müller, Ulrich; Yaghi, Omar M

    2015-03-09

    Metal-organic frameworks (MOFs) are constructed by linking inorganic units with organic linkers to make extended networks. Though more than 20 000 MOF structures have been reported most of these are ordered and largely composed of a limited number of different kinds building units, and very few have multiple different building units (heterogeneous). Although heterogeneity and multiplicity is a fundamental characteristic of biological systems, very few synthetic materials incorporate heterogeneity without losing crystalline order. Thus, the question arises: how do we introduce heterogeneity into MOFs without losing their ordered structure? This Review outlines strategies for varying the building units within both the backbone of the MOF and its pores to produce the heterogeneity that is sought after. The impact this heterogeneity imparts on the properties of a MOF is highlighted. We also provide an update on the MOF industry as part of this themed issue for the 150th anniversary of BASF.

  9. Structure and properties of an amorphous metal-organic framework.

    PubMed

    Bennett, Thomas D; Goodwin, Andrew L; Dove, Martin T; Keen, David A; Tucker, Matthew G; Barney, Emma R; Soper, Alan K; Bithell, Erica G; Tan, Jin-Chong; Cheetham, Anthony K

    2010-03-19

    ZIF-4, a metal-organic framework (MOF) with a zeolitic structure, undergoes a crystal-amorphous transition on heating to 300 degrees C. The amorphous form, which we term a-ZIF, is recoverable to ambient conditions or may be converted to a dense crystalline phase of the same composition by heating to 400 degrees C. Neutron and x-ray total scattering data collected during the amorphization process are used as a basis for reverse Monte Carlo refinement of an atomistic model of the structure of a-ZIF. The structure is best understood in terms of a continuous random network analogous to that of a-SiO2. Optical microscopy, electron diffraction and nanoindentation measurements reveal a-ZIF to be an isotropic glasslike phase capable of plastic flow on its formation. Our results suggest an avenue for designing broad new families of amorphous and glasslike materials that exploit the chemical and structural diversity of MOFs.

  10. Structure and Properties of an Amorphous Metal-Organic Framework

    NASA Astrophysics Data System (ADS)

    Bennett, Thomas D.; Goodwin, Andrew L.; Dove, Martin T.; Keen, David A.; Tucker, Matthew G.; Barney, Emma R.; Soper, Alan K.; Bithell, Erica G.; Tan, Jin-Chong; Cheetham, Anthony K.

    2010-03-01

    ZIF-4, a metal-organic framework (MOF) with a zeolitic structure, undergoes a crystal-amorphous transition on heating to 300°C. The amorphous form, which we term a-ZIF, is recoverable to ambient conditions or may be converted to a dense crystalline phase of the same composition by heating to 400°C. Neutron and x-ray total scattering data collected during the amorphization process are used as a basis for reverse Monte Carlo refinement of an atomistic model of the structure of a-ZIF. The structure is best understood in terms of a continuous random network analogous to that of a-SiO2. Optical microscopy, electron diffraction and nanoindentation measurements reveal a-ZIF to be an isotropic glasslike phase capable of plastic flow on its formation. Our results suggest an avenue for designing broad new families of amorphous and glasslike materials that exploit the chemical and structural diversity of MOFs.

  11. Designing Kitaev Spin Liquids in Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Yamada, Masahiko G.; Fujita, Hiroyuki; Oshikawa, Masaki

    2017-08-01

    Kitaev's honeycomb lattice spin model is a remarkable exactly solvable model, which has a particular type of spin liquid (Kitaev spin liquid) as the ground state. Although its possible realization in iridates and α -RuCl3 has been vigorously discussed recently, these materials have substantial non-Kitaev direct exchange interactions and do not have a spin liquid ground state. We propose metal-organic frameworks (MOFs) with Ru3 + (or Os3 + ), forming the honeycomb lattice as promising candidates for a more ideal realization of Kitaev-type spin models, where the direct exchange interaction is strongly suppressed. The great flexibility of MOFs allows generalization to other three-dimensional lattices for the potential realization of a variety of spin liquids, such as a Weyl spin liquid.

  12. Metal-organic frameworks: A new hydrogen storage system

    NASA Astrophysics Data System (ADS)

    Yaghi, Omar

    2004-03-01

    Metal-organic framework-5 (MOF-5) of composition Zn4O(BDC)3 (BDC = 1,4-benzenedi-carboxylate) with a cubic 3-D extended porous structure was found to be capable of adsorbing hydrogen up to 4.5 weight percent (17.2 hydrogen molecules per formula unit) at 78 K. At room temperature and pressures up to 20 bar this material has a hydrogen storage capacity which increases linearly as a function of the applied pressure up to 1.0 percent by weight at 20 bar. Inelastic Neutron Scattering spectroscopy of the rotational transitions of the adsorbed hydrogen molecules was performed on hydrogen loaded MOF-5 using doses equivalent to four, eight and twenty-four hydrogen molecules per formula unit at 10 K. The spectra show peaks at 10.3 and 12.3 meV that are sharper than those observed for hydrogen in other porous materials, indicating the presence of two well-defined binding sites (termed I and II), which we associate with hydrogen binding to zinc and the BDC linker, respectively. At the highest dose (twenty-four hydrogen molecules), the peak corresponding to site II splits into four peaks, suggesting that higher capacity for hydrogen may be achieved by the use of larger linkers. Indeed, preliminary studies on isoreticular (of the same topology) metal-organic framework-6 and 8 having cyclobutyl and benzene moieties respectively fused to the benzene of MOF-5 gave approximately double and quadruple (2.0 weight percent) the uptake found for MOF-5 at room temperature and 10 bar.

  13. Adsorption of Gases on Graphene and Metal Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Maiga, Sidi Mohamed

    Separation and adsorption of harmful gases from the environment are of great importance to industry and society. For this purpose, several materials are being explored. A large active surface area in the solid state candidates is an important requirement for efficient removal of gases. Owing to their large surface areas, Metal organic frameworks ( 2900 m2/g) and graphene ( 2600 m2/g), have emerged as two promising candidates for gas adsorption, separation and storage. The goal of this research is to investigate the capability of Metal Organic Frameworks and graphene for gas adsorption and separation; also to understand the properties of the molecules adsorbed on these two materials. We explore the adsorption of noble gases on graphene using Grand Canonical Monte Carlo simulations and also investigate the behavior of the monolayers on graphene. We obtain the phase diagrams of argon, krypton and xenon. We study the adsorption of carbon dioxide and methane molecules on graphene. Using Monte Carlo simulations and the Ideal Adsorb Solution Theory, we explore the selectivity of a binary mixture of CO2 and CH4 on graphene and estimate how the selectivity varies with temperature. We found high selectivity for CO2 at low temperature. At room temperature however the selectivity is low. We investigate the adsorption of CO2 and CH4 on a simplified model of the MOF-5 with systematic variations in the charge distribution, size and Lennard Jones parameters. We then test the selectivity of CO2 over CH4 and how it varies when we insert dipoles or quadrupole moments at the corners of the MOF-5. Our finding shows that the selectivity can be improved with adding dipoles or compressing the cell of the MOFs.

  14. Reconfigurable electronics using conducting metal-organic frameworks

    DOEpatents

    Allendorf, Mark D.; Talin, Albert Alec; Leonard, Francois; Stavila, Vitalie

    2017-07-18

    A device including a porous metal organic framework (MOF) disposed between two terminals, the device including a first state wherein the MOF is infiltrated by a guest species to form an electrical path between the terminals and a second state wherein the electrical conductivity of the MOF is less than the electrical conductivity in the first state. A method including switching a porous metal organic framework (MOF) between two terminals from a first state wherein a metal site in the MOF is infiltrated by a guest species that is capable of charge transfer to a second state wherein the MOF is less electrically conductive than in the first state.

  15. Imparting functionality to biocatalysts via embedding enzymes into nanoporous materials by a de novo approach: size-selective sheltering of catalase in metal-organic framework microcrystals.

    PubMed

    Shieh, Fa-Kuen; Wang, Shao-Chun; Yen, Chia-I; Wu, Chang-Cheng; Dutta, Saikat; Chou, Lien-Yang; Morabito, Joseph V; Hu, Pan; Hsu, Ming-Hua; Wu, Kevin C-W; Tsung, Chia-Kuang

    2015-04-08

    We develop a new concept to impart new functions to biocatalysts by combining enzymes and metal-organic frameworks (MOFs). The proof-of-concept design is demonstrated by embedding catalase molecules into uniformly sized ZIF-90 crystals via a de novo approach. We have carried out electron microscopy, X-ray diffraction, nitrogen sorption, electrophoresis, thermogravimetric analysis, and confocal microscopy to confirm that the ~10 nm catalase molecules are embedded in 2 μm single-crystalline ZIF-90 crystals with ~5 wt % loading. Because catalase is immobilized and sheltered by the ZIF-90 crystals, the composites show activity in hydrogen peroxide degradation even in the presence of protease proteinase K.

  16. Design and synthesis of metal-organic frameworks using metal-organic polyhedra as supermolecular building blocks.

    PubMed

    Perry, John J; Perman, Jason A; Zaworotko, Michael J

    2009-05-01

    This critical review highlights supermolecular building blocks (SBBs) in the context of their impact upon the design, synthesis, and structure of metal-organic materials (MOMs). MOMs, also known as coordination polymers, hybrid inorganic-organic materials, and metal-organic frameworks, represent an emerging class of materials that have attracted the imagination of solid-state chemists because MOMs combine unprecedented levels of porosity with a range of other functional properties that occur through the metal moiety and/or the organic ligand. First generation MOMs exploited the geometry of metal ions or secondary building units (SBUs), small metal clusters that mimic polygons, for the generation of MOMs. In this critical review we examine the recent (<5 years) adoption of much larger scale metal-organic polyhedra (MOPs) as SBBs for the construction of MOMs by highlighting how the large size and high symmetry of such SBBs can afford improved control over the topology of the resulting MOM and a new level of scale to the resulting framework (204 references).

  17. Highly mesoporous metal-organic framework assembled in a switchable solvent.

    PubMed

    Peng, Li; Zhang, Jianling; Xue, Zhimin; Han, Buxing; Sang, Xinxin; Liu, Chengcheng; Yang, Guanying

    2014-07-22

    The mesoporous metal-organic frameworks are a family of materials that have pore sizes ranging from 2 to 50 nm, which have shown promising applications in catalysis, adsorption, chemical sensing and so on. The preparation of mesoporous metal-organic frameworks usually needs the supramolecular or cooperative template strategy. Here we report the template-free assembly of mesoporous metal-organic frameworks by using CO2-expanded liquids as switchable solvents. The mesocellular metal-organic frameworks with large mesopores (13-23 nm) are formed, and their porosity properties can be easily adjusted by controlling CO2 pressure. Moreover, the use of CO2 can accelerate the reaction for metal-organic framework formation from metal salt and organic linker due to the viscosity-lowering effect of CO2, and the product can be recovered through CO2 extraction. The as-synthesized mesocellular metal-organic frameworks are highly active in catalysing the aerobic oxidation of benzylic alcohols under mild temperature at atmospheric pressure.

  18. Highly mesoporous metal-organic framework assembled in a switchable solvent

    NASA Astrophysics Data System (ADS)

    Peng, Li; Zhang, Jianling; Xue, Zhimin; Han, Buxing; Sang, Xinxin; Liu, Chengcheng; Yang, Guanying

    2014-07-01

    The mesoporous metal-organic frameworks are a family of materials that have pore sizes ranging from 2 to 50 nm, which have shown promising applications in catalysis, adsorption, chemical sensing and so on. The preparation of mesoporous metal-organic frameworks usually needs the supramolecular or cooperative template strategy. Here we report the template-free assembly of mesoporous metal-organic frameworks by using CO2-expanded liquids as switchable solvents. The mesocellular metal-organic frameworks with large mesopores (13-23 nm) are formed, and their porosity properties can be easily adjusted by controlling CO2 pressure. Moreover, the use of CO2 can accelerate the reaction for metal-organic framework formation from metal salt and organic linker due to the viscosity-lowering effect of CO2, and the product can be recovered through CO2 extraction. The as-synthesized mesocellular metal-organic frameworks are highly active in catalysing the aerobic oxidation of benzylic alcohols under mild temperature at atmospheric pressure.

  19. Metal-organic frameworks: Shuttling in the solid state

    NASA Astrophysics Data System (ADS)

    Olson, Mark A.

    2015-06-01

    Incorporating mechanically interlocked molecular shuttles within a metal-organic framework that has enough free space in the crystal lattice to permit volume-conserving translational motion sets the stage for defect-free molecular-electronic device fabrication and more.

  20. Omar Yaghi on Chemistry and Metal Organic Frameworks

    ScienceCinema

    Omar Yaghi

    2016-07-12

    In this edited version of the hour long talk, Omar Yaghi, director of the Molecular Foundry, sat down in conversation with Jeff Miller, head of Public Affairs, on July 11th, 2012 to discuss his fascination with the hidden world of chemistry and his work on Metal Organic Frameworks.

  1. Omar Yaghi on Chemistry and Metal Organic Frameworks

    SciTech Connect

    Omar Yaghi

    2012-07-23

    In this edited version of the hour long talk, Omar Yaghi, director of the Molecular Foundry, sat down in conversation with Jeff Miller, head of Public Affairs, on July 11th, 2012 to discuss his fascination with the hidden world of chemistry and his work on Metal Organic Frameworks.

  2. Metal-organic frameworks for lithium ion batteries and supercapacitors

    SciTech Connect

    Ke, Fu-Sheng; Wu, Yu-Shan; Deng, Hexiang

    2015-03-15

    Porous materials have been widely used in batteries and supercapacitors attribute to their large internal surface area (usually 100–1000 m{sup 2} g{sup −1}) and porosity that can favor the electrochemical reaction, interfacial charge transport, and provide short diffusion paths for ions. As a new type of porous crystalline materials, metal-organic frameworks (MOFs) have received huge attention in the past decade due to their unique properties, i.e. huge surface area (up to 7000 m{sup 2} g{sup −1}), high porosity, low density, controllable structure and tunable pore size. A wide range of applications including gas separation, storage, catalysis, and drug delivery benefit from the recent fast development of MOFs. However, their potential in electrochemical energy storage has not been fully revealed. Herein, the present mini review appraises recent and significant development of MOFs and MOF-derived materials for rechargeable lithium ion batteries and supercapacitors, to give a glimpse into these potential applications of MOFs. - Graphical abstract: MOFs with large surface area and high porosity can offer more reaction sites and charge carriers diffusion path. Thus MOFs are used as cathode, anode, electrolyte, matrix and precursor materials for lithium ion battery, and also as electrode and precursor materials for supercapacitors. - Highlights: • MOFs have potential in electrochemical area due to their high porosity and diversity. • We summarized and compared works on MOFs for lithium ion battery and supercapacitor. • We pointed out critical challenges and provided possible solutions for future study.

  3. Synthesis and Characterization of Functionalized Metal-organic Frameworks

    PubMed Central

    Karagiaridi, Olga; Bury, Wojciech; Sarjeant, Amy A.; Hupp, Joseph T.; Farha, Omar K.

    2014-01-01

    Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy. PMID:25225784

  4. Synthesis and characterization of functionalized metal-organic frameworks.

    PubMed

    Karagiaridi, Olga; Bury, Wojciech; Sarjeant, Amy A; Hupp, Joseph T; Farha, Omar K

    2014-09-05

    Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

  5. Selective gas adsorption and separation in metal-organic frameworks.

    PubMed

    Li, Jian-Rong; Kuppler, Ryan J; Zhou, Hong-Cai

    2009-05-01

    Adsorptive separation is very important in industry. Generally, the process uses porous solid materials such as zeolites, activated carbons, or silica gels as adsorbents. With an ever increasing need for a more efficient, energy-saving, and environmentally benign procedure for gas separation, adsorbents with tailored structures and tunable surface properties must be found. Metal-organic frameworks (MOFs), constructed by metal-containing nodes connected by organic bridges, are such a new type of porous materials. They are promising candidates as adsorbents for gas separations due to their large surface areas, adjustable pore sizes and controllable properties, as well as acceptable thermal stability. This critical review starts with a brief introduction to gas separation and purification based on selective adsorption, followed by a review of gas selective adsorption in rigid and flexible MOFs. Based on possible mechanisms, selective adsorptions observed in MOFs are classified, and primary relationships between adsorption properties and framework features are analyzed. As a specific example of tailor-made MOFs, mesh-adjustable molecular sieves are emphasized and the underlying working mechanism elucidated. In addition to the experimental aspect, theoretical investigations from adsorption equilibrium to diffusion dynamics via molecular simulations are also briefly reviewed. Furthermore, gas separations in MOFs, including the molecular sieving effect, kinetic separation, the quantum sieving effect for H2/D2 separation, and MOF-based membranes are also summarized (227 references).

  6. A fiber optic sensor with a metal organic framework as a sensing material for trace levels of water in industrial gases.

    PubMed

    Ohira, Shin-Ichi; Miki, Yusuke; Matsuzaki, Toru; Nakamura, Nao; Sato, Yu-ki; Hirose, Yasuo; Toda, Kei

    2015-07-30

    Industrial gases such as nitrogen, oxygen, argon, and helium are easily contaminated with water during production, transfer and use, because there is a high volume fraction of water in the atmosphere (approximately 1.2% estimated with the average annual atmospheric temperature and relative humidity). Even trace water (<1 parts per million by volume (ppmv) of H2O, dew point < -76 °C) in the industrial gases can cause quality problems in the process such as production of semiconductors. Therefore, it is important to monitor and to control trace water levels in industrial gases at each supplying step, and especially during their use. In the present study, a fiber optic gas sensor was investigated for monitoring trace water levels in industrial gases. The sensor consists of a film containing a metal organic framework (MOF). MOFs are made of metals coordinated to organic ligands, and have mesoscale pores that adsorb gas molecules. When the MOF, copper benzene-1,3,5-tricarboxylate (Cu-BTC), was used as a sensing material, we investigated the color of Cu-BTC with water adsorption changed both in depth and tone. Cu-BTC crystals appeared deep blue in dry gases, and then changed to light blue in wet gases. An optical gas sensor with the Cu-BTC film was developed using a light emitting diode as the light source and a photodiode as the light intensity detector. The sensor showed a reversible response to trace water, did not require heating to remove the adsorbed water molecules. The sample gas flow rate did not affect the sensitivity. The obtained limit of detection was 40 parts per billion by volume (ppbv). The response time for sample gas containing 2.5 ppmvH2O was 23 s. The standard deviation obtained for daily analysis of 1.0 ppmvH2O standard gas over 20 days was 9%. Furthermore, the type of industrial gas did not affect the sensitivity. These properties mean the sensor will be applicable to trace water detection in various industrial gases. Copyright © 2015 Elsevier B

  7. On the performance of Cu-BTC metal organic framework for carbon tetrachloride gas removal.

    PubMed

    Calero, Sofía; Martín-Calvo, Ana; Hamad, Said; García-Pérez, Elena

    2011-01-07

    The performance of Cu-BTC metal organic framework for carbon tetrachloride removal from air has been studied using molecular simulations. According to our results, this material shows extremely high adsorption selectivity in favour of carbon tetrachloride. We demonstrate that this selectivity can be further enhanced by selective blockage of the framework.

  8. Destruction of chemical warfare agents using metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Mondloch, Joseph E.; Katz, Michael J.; Isley, William C., III; Ghosh, Pritha; Liao, Peilin; Bury, Wojciech; Wagner, George W.; Hall, Morgan G.; Decoste, Jared B.; Peterson, Gregory W.; Snurr, Randall Q.; Cramer, Christopher J.; Hupp, Joseph T.; Farha, Omar K.

    2015-05-01

    Chemical warfare agents containing phosphonate ester bonds are among the most toxic chemicals known to mankind. Recent global military events, such as the conflict and disarmament in Syria, have brought into focus the need to find effective strategies for the rapid destruction of these banned chemicals. Solutions are needed for immediate personal protection (for example, the filtration and catalytic destruction of airborne versions of agents), bulk destruction of chemical weapon stockpiles, protection (via coating) of clothing, equipment and buildings, and containment of agent spills. Solid heterogeneous materials such as modified activated carbon or metal oxides exhibit many desirable characteristics for the destruction of chemical warfare agents. However, low sorptive capacities, low effective active site loadings, deactivation of the active site, slow degradation kinetics, and/or a lack of tailorability offer significant room for improvement in these materials. Here, we report a carefully chosen metal-organic framework (MOF) material featuring high porosity and exceptional chemical stability that is extraordinarily effective for the degradation of nerve agents and their simulants. Experimental and computational evidence points to Lewis-acidic ZrIV ions as the active sites and to their superb accessibility as a defining element of their efficacy.

  9. Molecular Transport in Metal Organic Framework Ma- terials

    NASA Astrophysics Data System (ADS)

    Canepa, P.; Nijem, N.; Chabal, Y. J.; Thonhauser, T.

    2013-03-01

    Metal organic frameworks (MOF) materials are a class of porous materials well suited for hydrogen storage and gas separation. While current work on MOFs focuses mostly on the adsorption properties of small molecules, their diffusion is still poorly understood. To elucidate the diffusion process, we study the diffusion of H2, CO2, and H2O in the nano-pores of MOF-74-Mg by combining ab initio simulations with infrared (IR) spectroscopy. We present computed adsorption energies and changes in the IR frequencies upon adsorption. We also discuss several diffusion mechanisms and their calculated barriers. We further verify the existence of the debated secondary binding sites for guest molecules and we discuss the role played by H2O. We find that H2O is much more likely to adsorb in the MOF than H2 and CO2, leading to a significant reduction of the adsorption capabilities of the MOF towards these target molecules, and hence resulting in limitations for practical applications. Overall, our computational findings are in very good agreement with experiment and they provide a fundamental understanding of the diffusion processes of small molecules in these nano-porous materials, with implication for the usability of MOFs in gas separation and storage applications.

  10. Large-scale screening of hypothetical metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Wilmer, Christopher E.; Leaf, Michael; Lee, Chang Yeon; Farha, Omar K.; Hauser, Brad G.; Hupp, Joseph T.; Snurr, Randall Q.

    2012-02-01

    Metal-organic frameworks (MOFs) are porous materials constructed from modular molecular building blocks, typically metal clusters and organic linkers. These can, in principle, be assembled to form an almost unlimited number of MOFs, yet materials reported to date represent only a tiny fraction of the possible combinations. Here, we demonstrate a computational approach to generate all conceivable MOFs from a given chemical library of building blocks (based on the structures of known MOFs) and rapidly screen them to find the best candidates for a specific application. From a library of 102 building blocks we generated 137,953 hypothetical MOFs and for each one calculated the pore-size distribution, surface area and methane-storage capacity. We identified over 300 MOFs with a predicted methane-storage capacity better than that of any known material, and this approach also revealed structure-property relationships. Methyl-functionalized MOFs were frequently top performers, so we selected one such promising MOF and experimentally confirmed its predicted capacity.

  11. Destruction of chemical warfare agents using metal-organic frameworks.

    PubMed

    Mondloch, Joseph E; Katz, Michael J; Isley, William C; Ghosh, Pritha; Liao, Peilin; Bury, Wojciech; Wagner, George W; Hall, Morgan G; DeCoste, Jared B; Peterson, Gregory W; Snurr, Randall Q; Cramer, Christopher J; Hupp, Joseph T; Farha, Omar K

    2015-05-01

    Chemical warfare agents containing phosphonate ester bonds are among the most toxic chemicals known to mankind. Recent global military events, such as the conflict and disarmament in Syria, have brought into focus the need to find effective strategies for the rapid destruction of these banned chemicals. Solutions are needed for immediate personal protection (for example, the filtration and catalytic destruction of airborne versions of agents), bulk destruction of chemical weapon stockpiles, protection (via coating) of clothing, equipment and buildings, and containment of agent spills. Solid heterogeneous materials such as modified activated carbon or metal oxides exhibit many desirable characteristics for the destruction of chemical warfare agents. However, low sorptive capacities, low effective active site loadings, deactivation of the active site, slow degradation kinetics, and/or a lack of tailorability offer significant room for improvement in these materials. Here, we report a carefully chosen metal-organic framework (MOF) material featuring high porosity and exceptional chemical stability that is extraordinarily effective for the degradation of nerve agents and their simulants. Experimental and computational evidence points to Lewis-acidic Zr(IV) ions as the active sites and to their superb accessibility as a defining element of their efficacy.

  12. Hydrogen storage by physisorption on Metal Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Dailly, Anne

    2008-03-01

    Cryo-adsorption systems based on materials with high specific surface areas have the main advantage that they can store and release hydrogen with fast kinetics and high reversibility over multiples cycles. Recently Metal Organic Frameworks (MOFs) have been proposed as promising adsorbents for hydrogen. These crystallographically well organized hybrid solids resulting from the three dimensional connection of inorganic clusters using organic linkers show the largest specific surface areas of all known crystalline solids. The determination of the relationships between physical properties (chemistry, structure, surface area ) of the MOFs and their hydrogen storage behavior is a key step in the characterization of these materials, if they are to be designed for hydrogen storage applications. Excess hydrogen sorption measurements for different MOFs will be presented. We show that maximum hydrogen uptake at high pressure and 77K does not always scale with the specific surface area. A linear correlation trend only apply within a class of specific materials and breaks down when the surface area measurement does not represent the surface sites that are available to H2. The influence of pore size and shape will also be discussed by comparing several MOFs with different structure types. The hydrogen adsorption and binding energy at low pressure are strongly dependent on the metal ions and the pore size.

  13. Smart Metal-Organic Framework Coatings: Triggered Antibiofilm Compound Release.

    PubMed

    Claes, Birgit; Boudewijns, Tom; Muchez, Laurens; Hooyberghs, Geert; Van der Eycken, Erik V; Vanderleyden, Jozef; Steenackers, Hans P; De Vos, Dirk E

    2017-02-08

    Metal-organic frameworks (MOFs) have a large potential for delivery of active molecules. Here, a MOF coating is investigated as a smart host matrix for triggered release of antibiofilm compounds. In addition to a coating consisting of the regular Fe-terephthalate MIL-88B(Fe), a new hydrophobic MIL-88B(Fe) coating is synthesized in hydrothermal conditions using palmitic acid as a lattice terminating group. These porous materials are used as a host matrix for the antibiofilm compound 5-(4-chlorophenyl)-N-(2-isobutyl)-2-aminoimidazole, which has a specific biofilm-inhibiting effect at concentrations at which no activity against planktonic cells is detected. The stability of MIL-88B(Fe) in distilled water and tryptic soy broth medium is investigated, together with the ability of iron(III) chelators to serve as a trigger for controlled decomposition of MIL-88B(Fe) by metal complexation. Organic iron chelators are used to mimic the iron chelating function of siderophores, which are specific molecules excreted by biofilm-forming bacteria. Trisodium citrate is able to chelate metal ions from the junctions of the framework. By sequestration of these metal ions, the host matrix is partially degraded, resulting in an antibiofilm compound release. Finally, the antibiofilm properties against Salmonella Typhimurium are validated by monitoring biofilm growth on MOF layers either loaded or not with aminoimidazole. A strong proof-of-concept is shown for efficient inhibition of biofilm growth through triggered antibiofilm compound release.

  14. A metal-organic framework-derived bifunctional oxygen electrocatalyst

    NASA Astrophysics Data System (ADS)

    Xia, Bao Yu; Yan, Ya; Li, Nan; Wu, Hao Bin; Lou, Xiong Wen (David); Wang, Xin

    2016-01-01

    Oxygen electrocatalysis is of great importance for many energy storage and conversion technologies, including fuel cells, metal-air batteries and water electrolysis. Replacing noble metal-based electrocatalysts with highly efficient and inexpensive non-noble metal-based oxygen electrocatalysts is critical for the practical applications of these technologies. Here we report a general approach for the synthesis of hollow frameworks of nitrogen-doped carbon nanotubes derived from metal-organic frameworks, which exhibit higher electrocatalytic activity and stability for oxygen reduction and evolution than commercial Pt/C electrocatalysts. The remarkable electrochemical properties are mainly attributed to the synergistic effect from chemical compositions and the robust hollow structure composed of interconnected crystalline nitrogen-doped carbon nanotubes. The presented strategy for controlled design and synthesis of metal-organic framework-derived functional nanomaterials offers prospects in developing highly active electrocatalysts in electrochemical energy devices.

  15. An Ising model for metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Höft, Nicolas; Horbach, Jürgen; Martín-Mayor, Victor; Seoane, Beatriz

    2017-08-01

    We present a three-dimensional Ising model where lines of equal spins are frozen such that they form an ordered framework structure. The frame spins impose an external field on the rest of the spins (active spins). We demonstrate that this "porous Ising model" can be seen as a minimal model for condensation transitions of gas molecules in metal-organic frameworks. Using Monte Carlo simulation techniques, we compare the phase behavior of a porous Ising model with that of a particle-based model for the condensation of methane (CH4) in the isoreticular metal-organic framework IRMOF-16. For both models, we find a line of first-order phase transitions that end in a critical point. We show that the critical behavior in both cases belongs to the 3D Ising universality class, in contrast to other phase transitions in confinement such as capillary condensation.

  16. In situ synthesized 3D heterometallic metal-organic framework (MOF) as a high-energy-density material shows high heat of detonation, good thermostability and insensitivity.

    PubMed

    Feng, Yaya; Liu, Xiangyu; Duan, Linqiang; Yang, Qi; Wei, Qing; Xie, Gang; Chen, Sanping; Yang, Xuwu; Gao, Shengli

    2015-02-07

    A reticular 3D heterometallic metal-organic framework (MOF), [Cu4Na(Mtta)5(CH3CN)]n () (N% = 40.08%), has been synthesized, using a 5-methyl tetrazole (Mtta) ligand formed from acetonitrile and azide, through in situ synthesis and structurally characterized by X-ray single crystal diffraction. The fluorescence spectra demonstrate that undergoes an interesting structural transformation in aqueous solution, yielding the compound [Cu4Na(Mtta)5H2O]n () as confirmed by (1)H NMR, IR and PXRD. Thermoanalysis showed that possesses excellent thermostability up to 335 °C. The calculated detonation properties and the sensitivity test illustrate that compound could be used as a potential explosive. In addition, the non-isothermal kinetics for were studied using the Kissinger and Ozawa-Doyle methods. The enthalpy of formation was obtained from the determination of the constant-volume combustion energy.

  17. Zeolite-like metal-organic frameworks (ZMOFs) based on the directed assembly of finite metal-organic cubes (MOCs).

    PubMed

    Alkordi, Mohamed H; Brant, Jacilynn A; Wojtas, Lukasz; Kravtsov, Victor Ch; Cairns, Amy J; Eddaoudi, Mohamed

    2009-12-16

    Two zeolite-like metal-organic frameworks (ZMOFs) with lta- and ast- topologies, zeolitic nets that can be interpreted as augmented edge-transitive 8-connected nets, are targeted through directed self-assembly of metal-organic cubes (MOCs) as supermolecular building blocks (SBBs).

  18. Single crystalline hollow metal-organic frameworks: a metal-organic polyhedron single crystal as a sacrificial template.

    PubMed

    Kim, Hyehyun; Oh, Minhak; Kim, Dongwook; Park, Jeongin; Seong, Junmo; Kwak, Sang Kyu; Lah, Myoung Soo

    2015-02-28

    Single crystalline hollow metal-organic frameworks (MOFs) with cavity dimensions on the order of several micrometers and hundreds of micrometers were prepared using a metal-organic polyhedron single crystal as a sacrificial hard template. The hollow nature of the MOF crystal was confirmed by scanning electron microscopy of the crystal sliced using a focused ion beam.

  19. Metal-organic frameworks for electrocatalytic reduction of carbon dioxide.

    PubMed

    Kornienko, Nikolay; Zhao, Yingbo; Kley, Christopher S; Zhu, Chenhui; Kim, Dohyung; Lin, Song; Chang, Christopher J; Yaghi, Omar M; Yang, Peidong

    2015-11-11

    A key challenge in the field of electrochemical carbon dioxide reduction is the design of catalytic materials featuring high product selectivity, stability, and a composition of earth-abundant elements. In this work, we introduce thin films of nanosized metal-organic frameworks (MOFs) as atomically defined and nanoscopic materials that function as catalysts for the efficient and selective reduction of carbon dioxide to carbon monoxide in aqueous electrolytes. Detailed examination of a cobalt-porphyrin MOF, Al2(OH)2TCPP-Co (TCPP-H2 = 4,4',4″,4‴-(porphyrin-5,10,15,20-tetrayl)tetrabenzoate) revealed a selectivity for CO production in excess of 76% and stability over 7 h with a per-site turnover number (TON) of 1400. In situ spectroelectrochemical measurements provided insights into the cobalt oxidation state during the course of reaction and showed that the majority of catalytic centers in this MOF are redox-accessible where Co(II) is reduced to Co(I) during catalysis.

  20. Metal-organic framework composites: from fundamentals to applications

    NASA Astrophysics Data System (ADS)

    Li, Shaozhou; Huo, Fengwei

    2015-04-01

    Metal-organic frameworks (MOFs) are a class of crystallized porous polymeric materials consisting of metal ions or clusters linked together by organic bridging ligands. Due to their permanent porosity, rich surface chemistry and tuneable pore sizes, MOFs have emerged as one type of important porous solid and have attracted intensive interests in catalysis, gas adsorption, separation and storage over the past two decades. When compared with pure MOFs, the combination of MOFs with functional species or matrix materials not only shows enhanced properties, but also broadens the applications of MOFs in new fields, such as bio-imaging, drug delivery and electrical catalysis, owing to the interactions of the functional species/matrix with the MOF structures. Although the synthesis, chemical modification and potential applications of MOFs have been reviewed previously, there is an increasing awareness on the synthesis and applications of their composites, which have rarely been reviewed. This review aims to fill this gap and discuss the fabrication, properties, and applications of MOF composites. The remaining challenges and future opportunities in this field, in terms of processing techniques, maximizing composite properties, and prospects for applications, have also been indicated.

  1. Controlling Thermal Expansion: A Metal-Organic Frameworks Route.

    PubMed

    Balestra, Salvador R G; Bueno-Perez, Rocio; Hamad, Said; Dubbeldam, David; Ruiz-Salvador, A Rabdel; Calero, Sofia

    2016-11-22

    Controlling thermal expansion is an important, not yet resolved, and challenging problem in materials research. A conceptual design is introduced here, for the first time, for the use of metal-organic frameworks (MOFs) as platforms for controlling thermal expansion devices that can operate in the negative, zero, and positive expansion regimes. A detailed computer simulation study, based on molecular dynamics, is presented to support the targeted application. MOF-5 has been selected as model material, along with three molecules of similar size and known differences in terms of the nature of host-guest interactions. It has been shown that adsorbate molecules can control, in a colligative way, the thermal expansion of the solid, so that changing the adsorbate molecules induces the solid to display positive, zero, or negative thermal expansion. We analyze in depth the distortion mechanisms, beyond the ligand metal junction, to cover the ligand distortions, and the energetic and entropic effect on the thermo-structural behavior. We provide an unprecedented atomistic insight on the effect of adsorbates on the thermal expansion of MOFs as a basic tool toward controlling the thermal expansion.

  2. Targeted manipulation of metal-organic frameworks to direct sorption properties.

    PubMed

    Schneemann, Andreas; Henke, Sebastian; Schwedler, Inke; Fischer, Roland A

    2014-04-04

    Metal-organic frameworks are promising materials for manifold applications. This Minireview highlights approaches for the fine-tuning of specific sorption properties (e.g. capacity, selectivity, and breathing behavior) of this interesting class of materials. Central aspects covered are the control over the crystal morphology, the targeted tuning of sorption properties by judicious choice of metal centers and linkers, and the preparation of host-guest systems. We want to introduce the reader to these topics on the basis of the manipulation of a handful of outstanding prototypical metal-organic frameworks. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Biomimetic mineralization of metal-organic frameworks as protective coatings for biomacromolecules

    PubMed Central

    Liang, Kang; Ricco, Raffaele; Doherty, Cara M.; Styles, Mark J.; Bell, Stephen; Kirby, Nigel; Mudie, Stephen; Haylock, David; Hill, Anita J.; Doonan, Christian J.; Falcaro, Paolo

    2015-01-01

    Enhancing the robustness of functional biomacromolecules is a critical challenge in biotechnology, which if addressed would enhance their use in pharmaceuticals, chemical processing and biostorage. Here we report a novel method, inspired by natural biomineralization processes, which provides unprecedented protection of biomacromolecules by encapsulating them within a class of porous materials termed metal-organic frameworks. We show that proteins, enzymes and DNA rapidly induce the formation of protective metal-organic framework coatings under physiological conditions by concentrating the framework building blocks and facilitating crystallization around the biomacromolecules. The resulting biocomposite is stable under conditions that would normally decompose many biological macromolecules. For example, urease and horseradish peroxidase protected within a metal-organic framework shell are found to retain bioactivity after being treated at 80 °C and boiled in dimethylformamide (153 °C), respectively. This rapid, low-cost biomimetic mineralization process gives rise to new possibilities for the exploitation of biomacromolecules. PMID:26041070

  4. Biomimetic mineralization of metal-organic frameworks as protective coatings for biomacromolecules

    NASA Astrophysics Data System (ADS)

    Liang, Kang; Ricco, Raffaele; Doherty, Cara M.; Styles, Mark J.; Bell, Stephen; Kirby, Nigel; Mudie, Stephen; Haylock, David; Hill, Anita J.; Doonan, Christian J.; Falcaro, Paolo

    2015-06-01

    Enhancing the robustness of functional biomacromolecules is a critical challenge in biotechnology, which if addressed would enhance their use in pharmaceuticals, chemical processing and biostorage. Here we report a novel method, inspired by natural biomineralization processes, which provides unprecedented protection of biomacromolecules by encapsulating them within a class of porous materials termed metal-organic frameworks. We show that proteins, enzymes and DNA rapidly induce the formation of protective metal-organic framework coatings under physiological conditions by concentrating the framework building blocks and facilitating crystallization around the biomacromolecules. The resulting biocomposite is stable under conditions that would normally decompose many biological macromolecules. For example, urease and horseradish peroxidase protected within a metal-organic framework shell are found to retain bioactivity after being treated at 80 °C and boiled in dimethylformamide (153 °C), respectively. This rapid, low-cost biomimetic mineralization process gives rise to new possibilities for the exploitation of biomacromolecules.

  5. Surface interactions and quantum kinetic molecular sieving for H2 and D2 adsorption on a mixed metal-organic framework material.

    PubMed

    Chen, Banglin; Zhao, Xuebo; Putkham, Apipong; Hong, Kunlun; Lobkovsky, Emil B; Hurtado, Eric J; Fletcher, Ashleigh J; Thomas, K Mark

    2008-05-21

    A rational strategy has been used to immobilize open metal sites in ultramicroporosity for stronger binding of multiple H 2 molecules per unsaturated metal site for H 2 storage applications. The synthesis and structure of a mixed zinc/copper metal-organic framework material Zn 3(BDC) 3[Cu(Pyen)] .(DMF) 5(H 2O) 5 (H 2BDC = 1,4 benzenedicarboxylic acid and PyenH 2 = 5-methyl-4-oxo-1,4-dihydro-pyridine-3-carbaldehyde) is reported. Desolvation provides a bimodal porous structure Zn 3(BDC) 3[Cu(Pyen)] (M'MOF 1) with narrow porosity (<0.56 nm) and an array of pores in the bc crystallographic plane where the adsorbate-adsorbent interactions are maximized by both the presence of open copper centers and overlap of the potential energy fields from pore walls. The H 2 and D 2 adsorption isotherms for M'MOF 1 at 77.3 and 87.3 K were reversible with virtually no hysteresis. Methods for determination of the isosteric enthalpies of H 2 and D 2 adsorption were compared. A virial model gave the best agreement (average deviation <1 standard deviation) with the isotherm data. This was used in conjunction with the van't Hoff isochore giving isosteric enthalpies at zero surface coverage of 12.29 +/- 0.53 and 12.44 +/- 0.50 kJ mol (-1) for H 2 and D 2 adsorption, respectively. This is the highest value so far observed for hydrogen adsorption on a porous material. The enthalpy of adsorption, decreases with increasing amount adsorbed to 9.5 kJ mol (-1) at approximately 1.9 mmol g (-1) (2 H 2 or D 2 molecules per Cu corresponding to adsorption on both sides of planar Cu open centers) and is virtually unchanged in the range 1.9-3.6 mmol g (-1). Virial analysis of isotherms at 87.3 K is also consistent with two H 2 or D 2 molecules being bound to each open Cu center. The adsorption kinetics follow a double exponential model, corresponding to diffusion along two types of pores, a slow component with high activation energy (13.35 +/- 0.59 kJ mol (-1)) for the narrow pores and a faster

  6. Investigating the potential of metal-organic framework material as an adsorbent for matrix solid-phase dispersion extraction of pesticides during analysis of dehydrated Hyptis pectinata medicinal plant by GC/MS.

    PubMed

    Aquino, Adriano; Ferreira, Jordana Alves; Navickiene, Sandro; Wanderley, Kaline A; de Sá, Gilberto F; Júnior, Severino A

    2012-01-01

    Metal-organic frameworks aluminum terephthalate MIL-53 and Cu-benzene-1,3,5-tricarboxylate (BTC) were tested for extraction of pyrimethanil, ametryn, dichlofluanid, tetraconazole, flumetralin, kresoximmethyl, and tebuconazole from the medicinal plant Hyptis pectinata, with analysis using GC/MS in the selected ion monitoring mode. Experiments carried out at different fortification levels (0.1, 0.5, and 1.0 microg/g) resulted in recoveries in the range 61 to 107% with RSD values between 3 and 12% for the metal-organic framework materials. Detection and quantification limits ranged from 0.02 to 0.07 and 0.05 to 0.1 microg/g, respectively, for the different pesticides studied. The method developed was linear over the range tested (0.04-20.0 microg/g), with correlation coefficients ranging from 0.9987 to 0.9998. Comparison of MIL-53 and Cu-BTC with C18-bonded silica showed good performance of the MIL-53 metal-organic framework as a sorbent for the pesticides tested.

  7. Hydrogen storage in microporous metal-organic frameworks.

    PubMed

    Rosi, Nathaniel L; Eckert, Juergen; Eddaoudi, Mohamed; Vodak, David T; Kim, Jaheon; O'Keeffe, Michael; Yaghi, Omar M

    2003-05-16

    Metal-organic framework-5 (MOF-5) of composition Zn4O(BDC)3 (BDC = 1,4-benzenedicarboxylate) with a cubic three-dimensional extended porous structure adsorbed hydrogen up to 4.5 weight percent (17.2 hydrogen molecules per formula unit) at 78 kelvin and 1.0 weight percent at room temperature and pressure of 20 bar. Inelastic neutron scattering spectroscopy of the rotational transitions of the adsorbed hydrogen molecules indicates the presence of two well-defined binding sites (termed I and II), which we associate with hydrogen binding to zinc and the BDC linker, respectively. Preliminary studies on topologically similar isoreticular metal-organic framework-6 and -8 (IRMOF-6 and -8) having cyclobutylbenzene and naphthalene linkers, respectively, gave approximately double and quadruple (2.0 weight percent) the uptake found for MOF-5 at room temperature and 10 bar.

  8. Hydrogen Storage in Microporous Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Rosi, Nathaniel L.; Eckert, Juergen; Eddaoudi, Mohamed; Vodak, David T.; Kim, Jaheon; O'Keeffe, Michael; Yaghi, Omar M.

    2003-05-01

    Metal-organic framework-5 (MOF-5) of composition Zn4O(BDC)3 (BDC = 1,4-benzenedicarboxylate) with a cubic three-dimensional extended porous structure adsorbed hydrogen up to 4.5 weight percent (17.2 hydrogen molecules per formula unit) at 78 kelvin and 1.0 weight percent at room temperature and pressure of 20 bar. Inelastic neutron scattering spectroscopy of the rotational transitions of the adsorbed hydrogen molecules indicates the presence of two well-defined binding sites (termed I and II), which we associate with hydrogen binding to zinc and the BDC linker, respectively. Preliminary studies on topologically similar isoreticular metal-organic framework-6 and -8 (IRMOF-6 and -8) having cyclobutylbenzene and naphthalene linkers, respectively, gave approximately double and quadruple (2.0 weight percent) the uptake found for MOF-5 at room temperature and 10 bar.

  9. Metallacarboranes: Towards promising hydrogen storage metal organic framework

    NASA Astrophysics Data System (ADS)

    Singh, Abhishek; Sadrzadeh, Arta; Yakobson, Boris

    2011-03-01

    Using first principles calculations we show the high hydrogen storage capacity of metallacarboranes, where the transition metal (TM) atoms bind hydrogen via Kubas interaction. The average binding energy of ~ 0.3 eV/H favorably lies within the reversible adsorption range The Sc and Ti are found to be the optimum metal atoms maximizing the number of stored H2 molecules. Depending upon the structure, metallacarboranes can adsorb up to 8 wt% of hydrogen, which exceeds DOE goal for 2015. Being integral part of the cage, TMs do not suffer from the aggregation problem. Furthermore, the presence of carbon atom in the cages permits linking the metallacarboranes to form metal organic frameworks (MOF), thus able to adsorb hydrogen via Kubas interaction, in addition to van der Waals physisorption. A. K. Singh, A. Sadrzadeh, and B. I. Yakobson, Metallacarboranes: Toward Promising Hydrogen Storage Metal Organic Frameworks, JACS 132,14126 (2010).

  10. Mechanochemical synthesis of an yttrium based metal-organic framework.

    PubMed

    Singh, Niraj K; Hardi, Meenakshi; Balema, Viktor P

    2013-02-01

    For the first time a metal hydride has been used for the preparation of a metal-organic framework. MIL-78 has been synthesized by the solid-state mechanochemical reaction between yttrium hydride and trimesic acid. The process does not involve solvents and does not generate liquid by-products, thus proving the viability of the solid-state approach to the synthesis of MOFs.

  11. Metal-Organic Frameworks for Thin-Layer Chromatographic Applications.

    PubMed

    Schenk, Claudia; Kutzscher, Christel; Drache, Franziska; Helten, Stella; Senkovska, Irena; Kaskel, Stefan

    2017-01-25

    Preparation of thin-layer chromatographic (TLC) plates based on metal-organic frameworks (MOFs) as porous stationary phases is described. DUT-67 (DUT = Dresden University of Technology), a zirconium based MOF, was used in combination with a fluorescent indicator as stationary phase for analyzing a small selection of a wide spectrum of relevant analytes. The successful separation of benzaldehyde from trans-cinnamaldehyde and 4-aminophenol from 2-aminotoluene is reported as a model system using optimized eluent mixtures containing acetic acid.

  12. Metal organic framework MIL-101 for radioiodine capture and storage

    NASA Astrophysics Data System (ADS)

    Assaad, Thaer; Assfour, Bassem

    2017-09-01

    we report on the use of metal organic frameworks(MOFs) for radioiodine recovery and storage. One MOF (namely MIL-101) was prepared and investigated in detail to demonstrate the iodine removal efficiency and capacity of MOFs. The typical sorption kinetics and uptake isotherms were measured using radioactive iodine (123 I) for the first time. Our measurements indicate that MOFs can capture and store radioiodine in very high efficiency and fast kinetics.

  13. Energy Storage during Compression of Metal-Organic Frameworks.

    PubMed

    Miao, Yu-Run; Su, Zhi; Suslick, Kenneth S

    2017-04-05

    Practical applications of metal-organic framework (MOF) materials require an in-depth understanding of their mechanical properties. We have investigated the mechanical properties and energy absorption behavior of single crystals of four isostructural UiO-type MOFs under uniaxial compression. In situ nanocompression experiments were used to measure the mechanical behavior of individual MOF nanocrystals under compression within a transmission electron microscope. The plasticity and endothermicity during deformation of MOFs shows a surprising potential for absorption and dissipation of mechanical shock. At compressive stress below 2 GPa, relatively small amounts of energy (<0.3 kJ/g) are absorbed by the compression of these MOFs. As the stress was increased, however, the energy absorption was significantly enhanced. Above 2 GPa, the energy absorption typically reaches 3-4 kJ/g; for comparison, the energy release in the explosion of TNT is ∼4 kJ/g. Gram for gram, MOFs can absorb as much energy as a high explosive can release.

  14. Multi-shelled Hollow Metal-Organic Frameworks.

    PubMed

    Liu, Wenxian; Huang, Jijiang; Yang, Qiu; Wang, Shiji; Sun, Xiaoming; Zhang, Weina; Liu, Junfeng; Huo, Fengwei

    2017-05-08

    Hollow metal-organic frameworks (MOFs) are promising materials with sophisticated structures, such as multiple shells, that cannot only enhance the properties of MOFs but also endow them with new functions. Herein, we show a rational strategy to fabricate multi-shelled hollow chromium (III) terephthalate MOFs (MIL-101) with single-crystalline shells through step-by-step crystal growth and subsequent etching processes. This strategy relies on the creation of inhomogeneous MOF crystals in which the outer layer is chemically more robust than the inner layer and can be selectively etched by acetic acid. The regulation of MOF nucleation and crystallization allows the tailoring of the cavity size and shell thickness of each layer. The resultant multi-shelled hollow MIL-101 crystals show significantly enhanced catalytic activity during styrene oxidation. The insight gained from this systematic study will aid in the rational design and synthesis of other multi-shelled hollow structures and the further expansion of their applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Electrocatalytic Metal-Organic Frameworks for Energy Applications.

    PubMed

    Downes, Courtney A; Marinescu, Smaranda C

    2017-10-02

    With global energy demand expected to rise drastically over the next several decades, the development of a sustainable energy system to meet this rise is paramount. Renewable energy sources can be coupled with electrochemical conversion processes to store energy in chemical bonds. To promote these difficult transformations, electrocatalysts that operate at high conversion rates and efficiency are required. Metal-organic frameworks (MOFs) have emerged as a promising class of materials, however, the insulating nature of MOFs has limited their application as electrocatalysts. The recent development of conductive MOFs has led to several electrocatalytic MOFs that display activity comparable to the best performing heterogeneous catalysts. Although many electrocatalytic MOFs exhibit low activity and stability, the few successful examples highlight the possibility of MOF electrocatalysts as replacements for noble-metal based catalysts in commercial energy converting devices. We review here the use of pristine MOFs as electrocatalysts to facilitate important energy-related reactions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Synthetic Modularity of Protein-Metal-Organic Frameworks.

    PubMed

    Bailey, Jake B; Zhang, Ling; Chiong, Jerika A; Ahn, Sunhyung; Tezcan, F Akif

    2017-06-21

    Previously, we adopted the construction principles of metal-organic frameworks (MOFs) to design a 3D crystalline protein lattice in which pseudospherical ferritin nodes decorated on their C3 symmetric vertices with Zn coordination sites were connected via a ditopic benzene-dihydroxamate linker. In this work, we have systematically varied both the metal ions presented at the vertices of the ferritin nodes (Zn(II), Ni(II), and Co(II)) and the synthetic dihydroxamate linkers, which yielded an expanded library of 15 ferritin-MOFs with the expected body-centered (cubic or tetragonal) lattice arrangements. Crystallographic and small-angle X-ray scattering (SAXS) analyses indicate that lattice symmetries and dimensions of ferritin-MOFs can be dictated by both the metal and linker components. SAXS measurements on bulk crystalline samples reveal that some ferritin-MOFs can adopt multiple lattice conformations, suggesting dynamic behavior. This work establishes that the self-assembly of ferritin-MOFs is highly robust and that the synthetic modularity that underlies the structural diversity of conventional MOFs can also be applied to the self-assembly of protein-based crystalline materials.

  17. Unusual adsorption behavior on metal-organic frameworks.

    PubMed

    Fairen-Jimenez, David; Seaton, Nigel A; Düren, Tina

    2010-09-21

    Metal-organic frameworks (MOFs) have shown adsorption behavior that is not observed in other microporous materials such as zeolites or activated carbons. This study used grand canonical Monte Carlo simulation to evaluate a particular form of behavior, which corresponds to the presence of unusual type V adsorption isotherms. Study of a series of MOFs in the IRMOF family, containing chemically similar linkers of different length, showed that the presence of type V adsorption depends on a fine balance between the strength of the fluid-fluid and fluid-solid interactions, which in turn is a strong function of the length of the linker and therefore the pore size. A transition from type V behavior to the more common type I behavior is observed as the temperature increases. The temperature at which this transition occurs increases, and the transition becomes more diffuse, as the length of the linker increases. This type V behavior leads to an interesting possibility in the design of MOF adsorbents for use in gas separation and gas storage applications.

  18. In situ synthesized 3D metal-organic frameworks (MOFs) constructed from transition metal cations and tetrazole derivatives: a family of insensitive energetic materials.

    PubMed

    Xu, Yuangang; Liu, Wei; Li, Dongxue; Chen, Houhe; Lu, Ming

    2017-08-22

    The combination of the hydrothermal method with in situ synthesis has been successfully employed to prepare a family of tetrazole-based energetic metal-organic frameworks (EMOFs) ([Ag(Mtta)]n, 1; [Cd5(Mtta)9]n, 2; [Pb3(bta)2(O)2(H2O)]n, 3; and [Pb(tztr)2(H2O)]n, 4) through [2 + 3] cycloaddition of azide anions and nitrile groups. All the synthesized EMOFs were characterized by single crystal X-ray diffraction, IR spectroscopy, elemental analysis (EA), different scanning calorimetry (DSC), and thermogravimetry (TG). Both complexes 1 and 4 consist of reticular two-dimensional (2D) layers that are linked by π-π overlap interactions between the ligands in neighbouring layers to form 3D supramolecular structures. In contrast, complexes 2 and 3 are 3D frameworks. The in situ formation of ligands bta and tztr has been described for the first time. Remarkably, thermogravimetric measurements demonstrated that the EMOFs 1-4 possess excellent thermostabilities with high decomposition temperatures up to 354, 389, and 372 °C for 1, 2, and 4, respectively. Sensitivity tests revealed that all the EMOFs are extremely insensitive.

  19. Metal-Organic Nanosheets Formed via Defect-Mediated Transformation of a Hafnium Metal-Organic Framework.

    PubMed

    Cliffe, Matthew J; Castillo-Martínez, Elizabeth; Wu, Yue; Lee, Jeongjae; Forse, Alexander C; Firth, Francesca C N; Moghadam, Peyman Z; Fairen-Jimenez, David; Gaultois, Michael W; Hill, Joshua A; Magdysyuk, Oxana V; Slater, Ben; Goodwin, Andrew L; Grey, Clare P

    2017-04-19

    We report a hafnium-containing MOF, hcp UiO-67(Hf), which is a ligand-deficient layered analogue of the face-centered cubic fcu UiO-67(Hf). hcp UiO-67 accommodates its lower ligand:metal ratio compared to fcu UiO-67 through a new structural mechanism: the formation of a condensed "double cluster" (Hf12O8(OH)14), analogous to the condensation of coordination polyhedra in oxide frameworks. In oxide frameworks, variable stoichiometry can lead to more complex defect structures, e.g., crystallographic shear planes or modules with differing compositions, which can be the source of further chemical reactivity; likewise, the layered hcp UiO-67 can react further to reversibly form a two-dimensional metal-organic framework, hxl UiO-67. Both three-dimensional hcp UiO-67 and two-dimensional hxl UiO-67 can be delaminated to form metal-organic nanosheets. Delamination of hcp UiO-67 occurs through the cleavage of strong hafnium-carboxylate bonds and is effected under mild conditions, suggesting that defect-ordered MOFs could be a productive route to porous two-dimensional materials.

  20. Multiphoton absorption in graphene and metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Weiqiang, Chen

    Materials possessing large multiphoton absorption are of direct relevance to both photonics applications and materials physics. In this dissertation, we present our investigations into two novel materials: namely, (1) graphene and (2) metal-organic frameworks (MOFs). The dissertation divides into two parts. The first part of the dissertation reports our systematical Z-scan measurements onto two-photon absorption (2PA) in graphene in the spectral range of 435-1100 nm with femtosecond laser pulses. We report that the measured 2PA coefficients of graphene in the near-infrared (NIR) range of 800-1100 nm can be explained by a theoretical model based on the optical transitions near the Dirac point (K point). We also determine the 2PA coefficients of graphene in the visible spectrum (435-700 nm) and observe an enhancement induced by the excitonic Fano resonance at the saddle point (M point). By applying the second-order, time-dependent perturbation theory on interband transitions among three states near the saddle point, we develop a semi-empirical model to take excitons in graphene into consideration. And the model is in agreement with the photon-energy dependence of the observed 2PA spectrum with a scaling factor of B = (1 5) x 102 cm/MW/eV5. Our results verify, for the first time, that the excitonic Fano resonance plays an important role for the 2PA of graphene in the visible spectrum. Besides, we also detail our measurements on the spectral dependence of one-photon absorption (1PA) saturation in graphene over the visible-NIR range. A quadratic photon energy dependence of the measured saturation intensity/fluence is observed over the investigated spectral range. The underlying photo-dynamics is discussed. In the second part of the dissertation, we investigate multiphoton excited photoluminescence (MEPL) from three solid-state crystals of metal-organic frameworks (MOFs): (1) [Zn2(trans,trans-4,4 stilbenedicarboxylic acid (SDC))2(trans, trans-9, 10-bis (4-pyridylethenyl

  1. Integration of metal-organic frameworks into an electrochemical dielectric thin film for electronic applications

    PubMed Central

    Li, Wei-Jin; Liu, Juan; Sun, Zhi-Hua; Liu, Tian-Fu; Lü, Jian; Gao, Shui-Ying; He, Chao; Cao, Rong; Luo, Jun-Hua

    2016-01-01

    The integration of porous metal-organic frameworks onto the surface of materials, for use as functional devices, is currently emerging as a promising approach for gas sensing and flexible displays. However, research focused on potential applications in electronic devices is in its infancy. Here we present a facile strategy by which interpenetrated, crystalline metal-organic framework films are deposited onto conductive metal-plate anodes via in situ temperature-controlled electrochemical assembly. The nanostructure of the surface as well as the thickness and uniformity of the film are well controlled. More importantly, the resulting films exhibit enhanced dielectric properties compared to traditional inorganic or organic gate dielectrics. This study demonstrates the successful implementation of the rational design of metal-organic framework thin films on conductive supports with high-performance dielectric properties. PMID:27282348

  2. Integration of metal-organic frameworks into an electrochemical dielectric thin film for electronic applications

    NASA Astrophysics Data System (ADS)

    Li, Wei-Jin; Liu, Juan; Sun, Zhi-Hua; Liu, Tian-Fu; Lü, Jian; Gao, Shui-Ying; He, Chao; Cao, Rong; Luo, Jun-Hua

    2016-06-01

    The integration of porous metal-organic frameworks onto the surface of materials, for use as functional devices, is currently emerging as a promising approach for gas sensing and flexible displays. However, research focused on potential applications in electronic devices is in its infancy. Here we present a facile strategy by which interpenetrated, crystalline metal-organic framework films are deposited onto conductive metal-plate anodes via in situ temperature-controlled electrochemical assembly. The nanostructure of the surface as well as the thickness and uniformity of the film are well controlled. More importantly, the resulting films exhibit enhanced dielectric properties compared to traditional inorganic or organic gate dielectrics. This study demonstrates the successful implementation of the rational design of metal-organic framework thin films on conductive supports with high-performance dielectric properties.

  3. Ab-initio Study of Known and Hypothetical Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Fuentes-Cabrera, Miguel; Nicholson, Don M.

    2004-03-01

    Rosi et al. [1] have found that microporous Metal-Organic Frameworks (MOF) materials are candidates for hydrogen storage applications. In particular, MOF-5 was found to adsorb hydrogen up to 4.5 weight percent at 78 kelvin and 1.0 weight percent at room temperature and pressure of 20 bar. We use ab-initio techniques to investigate hydrogen adsorption, stability, and the electronic properties of known and hypothetical Metal-Organic Frameworks. [1] N.L. Rosi, J. Eckert, M. Eddaoudi, D.T. Vodak, J. Kim, M. O'Keeffe, and O.M. Yaghi

  4. Preparation and applications of monolithic structures containing metal-organic frameworks.

    PubMed

    Lv, Yongqin; Tan, Xinyi; Svec, Frantisek

    2017-01-01

    Metal-organic frameworks are a new category of advanced porous materials with large surface areas and porosities, uniform pore sizes, tunable surface chemistry, and structural diversity. In combination with monoliths, they allow the fine tuning of desired interactions required in a variety of applications. This review article summarizes results of recent studies focused on synthetic strategies enabling incorporation of metal-organic frameworks in monolithic structures. A diverse array of applications including chromatographic separation, solid-phase microextraction, sample enrichment, heterogeneous catalysis, and enzymatic catalysis are also described. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Pore Space Partition in Metal-Organic Frameworks.

    PubMed

    Zhai, Quan-Guo; Bu, Xianhui; Zhao, Xiang; Li, Dong-Sheng; Feng, Pingyun

    2017-02-21

    Metal-organic framework (MOF) materials have emerged as one of the favorite crystalline porous materials (CPM) because of their compositional and geometric tunability and many possible applications. In efforts to develop better MOFs for gas storage and separation, a number of strategies including creation of open metal sites and implantation of Lewis base sites have been used to tune host-guest interactions. In addition to these chemical factors, the geometric features such as pore size and shape, surface area, and pore volume also play important roles in sorption energetics and uptake capacity. For efficient capture of small gas molecules such as carbon dioxide under ambient conditions, large surface area or high pore volume are often not needed. Instead, maximizing host-guest interactions or the density of binding sites by encaging gas molecules in snug pockets of pore space can be a fruitful approach. To put this concept into practice, the pore space partition (PSP) concept has been proposed and has achieved a great experimental success. In this account, we will highlight many efforts to implement PSP in MOFs and impact of PSP on gas uptake performance. In the synthetic design of PSP, it is helpful to distinguish between factors that contribute to the framework formation and factors that serve the purpose of PSP. Because of the need for complementary structural roles, the synthesis of MOFs with PSP often involves multicomponent systems including mixed ligands, mixed inorganic nodes, or both. It is possible to accomplish both framework formation and PSP with a single type of polyfunctional ligands that use some functional groups (called framework-forming group) for framework formation and the remaining functional groups (called pore-partition group) for PSP. Alternatively, framework formation and PSP can be shouldered by different chemical species. For example, in a mixed-ligand system, one ligand (called framework-forming agent) can play the role of the

  6. Metal-organic framework derived ZnO/ZnFe2O4/C nanocages as stable cathode material for reversible lithium-oxygen batteries.

    PubMed

    Yin, Wei; Shen, Yue; Zou, Feng; Hu, Xianluo; Chi, Bo; Huang, Yunhui

    2015-03-04

    Tremendous efforts have been devoted to exploring various Li-O2 cathode catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). However, most of the high-activity ORR/OER catalysts can also accelerate side-reactions, such as electrolyte degradation on cycling. To address this issue, we change our strategy from pursuing highly active catalysts to developing stable cathodes that are compatible with the electrolyte. In this work, hierarchical mesoporous ZnO/ZnFe2O4/C (ZZFC) nanocages are synthesized from the templates of metal-organic framework (MOF) nanocages. Such ZZFC nanocages have lower ORR/OER catalytic activity as compared with the widely used catalysts for fuel cells, but they do not catalyze the degradation of organic electrolyte during operation. Furthermore, the optimized porosity and conductivity can fit well the needs of the Li-O2 cathode. When employed in a Li-O2 battery, the ZZFC cathode delivers a primary discharge/charge capacity exceeding 11 000 mAh g(-1) at a current density of 300 mA g(-1) and an improved cyclability with capacity of 5000 mAh g(-1) for 15 cycles. The superior electrochemical performance is ascribed to the hierarchical porosity and little degradation of the organic electrolyte.

  7. Transition metal complexes supported on metal-organic frameworks for heterogeneous catalysts

    DOEpatents

    Farha, Omar K.; Hupp, Joseph T.; Delferro, Massimiliano; Klet, Rachel C.

    2017-02-07

    A robust mesoporous metal-organic framework comprising a hafnium-based metal-organic framework and a single-site zirconium-benzyl species is provided. The hafnium, zirconium-benzyl metal-organic framework is useful as a catalyst for the polymerization of an alkene.

  8. Redox-promoted associative assembly of metal-organic materials.

    PubMed

    Glavinović, Martin; Qi, Feng; Katsenis, Athanassios D; Friščić, Tomislav; Lumb, Jean-Philip

    2016-01-01

    We develop an associative synthesis of metal-organic materials that combines solid-state metal oxidation and coordination-driven self-assembly into a one-step, waste-free transformation. The methodology hinges on the unique reactivity of ortho-quinones, which we introduce as versatile oxidants for mechanochemical synthesis. Our strategy opens a previously unexplored route to paramagnetic metal-organic materials from elementary metals.

  9. Porphyrin-Based Metal-Organic Frameworks as Heterogeneous Catalysts in Oxidation Reactions.

    PubMed

    Pereira, Carla F; Simões, Mário M Q; Tomé, João P C; Almeida Paz, Filipe A

    2016-10-12

    Porphyrin-based Metal-Organic Frameworks (Por-MOFs) constitute a special branch of the wide MOF family that has proven its own value and high potential in different applications. In this mini-review the application of these materials as catalysts in oxidation reactions is highlighted.

  10. Investigation of metal hydride nanoparticles templated in metal organic frameworks.

    SciTech Connect

    Jacobs, Benjamin W.; Herberg, Julie L.; Highley, Aaron M.; Grossman, Jeffrey; Wagner, Lucas; Bhakta, Raghu; Peaslee, D.; Allendorf, Mark D.; Liu, X.; Behrens, Richard, Jr.; Majzoub, Eric H.

    2010-11-01

    Hydrogen is proposed as an ideal carrier for storage, transport, and conversion of energy. However, its storage is a key problem in the development of hydrogen economy. Metal hydrides hold promise in effectively storing hydrogen. For this reason, metal hydrides have been the focus of intensive research. The chemical bonds in light metal hydrides are predominantly covalent, polar covalent or ionic. These bonds are often strong, resulting in high thermodynamic stability and low equilibrium hydrogen pressures. In addition, the directionality of the covalent/ionic bonds in these systems leads to large activation barriers for atomic motion, resulting in slow hydrogen sorption kinetics and limited reversibility. One method for enhancing reaction kinetics is to reduce the size of the metal hydrides to nano scale. This method exploits the short diffusion distances and constrained environment that exist in nanoscale hydride materials. In order to reduce the particle size of metal hydrides, mechanical ball milling is widely used. However, microscopic mechanisms responsible for the changes in kinetics resulting from ball milling are still being investigated. The objective of this work is to use metal organic frameworks (MOFs) as templates for the synthesis of nano-scale NaAlH4 particles, to measure the H2 desorption kinetics and thermodynamics, and to determine quantitative differences from corresponding bulk properties. Metal-organic frameworks (MOFs) offer an attractive alternative to traditional scaffolds because their ordered crystalline lattice provides a highly controlled and understandable environment. The present work demonstrates that MOFs are stable hosts for metal hydrides and their reactive precursors and that they can be used as templates to form metal hydride nanoclusters on the scale of their pores (1-2 nm). We find that using the MOF HKUST-1 as template, NaAlH4 nanoclusters as small as 8 formula units can be synthesized inside the pores. A detailed picture of

  11. Metal-organic frameworks as selectivity regulators for hydrogenation reactions

    NASA Astrophysics Data System (ADS)

    Zhao, Meiting; Yuan, Kuo; Wang, Yun; Li, Guodong; Guo, Jun; Gu, Lin; Hu, Wenping; Zhao, Huijun; Tang, Zhiyong

    2016-11-01

    Owing to the limited availability of natural sources, the widespread demand of the flavouring, perfume and pharmaceutical industries for unsaturated alcohols is met by producing them from α,β-unsaturated aldehydes, through the selective hydrogenation of the carbon-oxygen group (in preference to the carbon-carbon group). However, developing effective catalysts for this transformation is challenging, because hydrogenation of the carbon-carbon group is thermodynamically favoured. This difficulty is particularly relevant for one major category of heterogeneous catalyst: metal nanoparticles supported on metal oxides. These systems are generally incapable of significantly enhancing the selectivity towards thermodynamically unfavoured reactions, because only the edges of nanoparticles that are in direct contact with the metal-oxide support possess selective catalytic properties; most of the exposed nanoparticle surfaces do not. This has inspired the use of metal-organic frameworks (MOFs) to encapsulate metal nanoparticles within their layers or inside their channels, to influence the activity of the entire nanoparticle surface while maintaining efficient reactant and product transport owing to the porous nature of the material. Here we show that MOFs can also serve as effective selectivity regulators for the hydrogenation of α,β-unsaturated aldehydes. Sandwiching platinum nanoparticles between an inner core and an outer shell composed of an MOF with metal nodes of Fe3+, Cr3+ or both (known as MIL-101; refs 19, 20, 21) results in stable catalysts that convert a range of α,β-unsaturated aldehydes with high efficiency and with significantly enhanced selectivity towards unsaturated alcohols. Calculations reveal that preferential interaction of MOF metal sites with the carbon-oxygen rather than the carbon-carbon group renders hydrogenation of the former by the embedded platinum nanoparticles a thermodynamically favoured reaction. We anticipate that our basic design

  12. Metal-Organic Frameworks for Highly Selective Separations

    SciTech Connect

    Omar M. Yaghi

    2009-09-28

    This grant was focused on the study of metal-organic frameworks with these specific objectives. (1) To examine the use of MOFs with well-defined open metal sites for binding of gases and small organics. (2) To develop a strategy for producing MOFs that combine large pore size with high surface area for their use in gas adsorption and separation of polycyclic organic compounds. (3) To functionalize MOFs for the storage of inert gases such as methane. A brief outline of our progress towards these objectives is presented here as it forms part of the basis for the ideas to be developed under the present proposal.

  13. Surface functionalization of metal organic frameworks for mixed matrix membranes

    DOEpatents

    Albenze, Erik; Lartey, Michael; Li, Tao; Luebke, David R.; Nulwala, Hunaid B.; Rosi, Nathaniel L.; Venna, Surendar R.

    2017-03-21

    Mixed Matrix Membrane (MMM) are composite membranes for gas separation and comprising a quantity of inorganic filler particles, in particular metal organic framework (MOF), dispersed throughout a polymer matrix comprising one or more polymers. This disclosure is directed to MOF functionalized through addition of a pendant functional group to the MOF, in order to improve interaction with a surrounding polymer matrix in a MMM. The improved interaction aids in avoiding defects in the MMM due to incompatible interfaces between the polymer matrix and the MOF particle, in turn increasing the mechanical and gas separation properties of the MMM. The disclosure is also directed to a MMM incorporating the surface functionalized MOF.

  14. Integration of Biomolecules with Metal-Organic Frameworks.

    PubMed

    Zhuang, Jia; Young, Allison P; Tsung, Chia-Kuang

    2017-08-01

    Owing to the progressive development of metal-organic-frameworks (MOFs) synthetic processes and considerable potential applications in last decade, integrating biomolecules into MOFs has recently gain considerable attention. Biomolecules, including lipids, oligopeptides, nucleic acids, and proteins have been readily incorporated into MOF systems via versatile formulation methods. The formed biomolecule-MOF hybrid structures have shown promising prospects in various fields, such as antitumor treatment, gene delivery, biomolecular sensing, and nanomotor device. By optimizing biomolecule integration methods while overcoming existing challenges, biomolecule-integrated MOF platforms are very promising to generate more practical applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Carbon Dioxide Separation with Novel Microporous Metal Organic Frameworks

    SciTech Connect

    Richard Willis; Annabelle Benin; John Low; Ganesh Venimadhavan; Syed Faheem; David Lesch; Adam Matzger; Randy Snurr

    2008-02-04

    The goal of this program was to develop a low cost novel sorbent to remove carbon dioxide from flue gas and gasification streams in electric utilities. Porous materials named metal-organic frameworks (MOFs) were found to have good capacity and selectivity for the capture of carbon dioxide. Several materials from the initial set of reference MOFs showed extremely high CO{sub 2} adsorption capacities and very desirable linear isotherm shapes. Sample preparation occurred at a high level, with a new family of materials suitable for intellectual property protection prepared and characterized. Raman spectroscopy was shown to be useful for the facile characterization of MOF materials during adsorption and especially, desorption. Further, the development of a Raman spectroscopic-based method of determining binary adsorption isotherms was initiated. It was discovered that a stronger base functionality will need to be added to MOF linkers in order to enhance CO{sub 2} selectivity over other gases via a chemisorption mechanism. A concentrated effort was expended on being able to accurately predict CO{sub 2} selectivities and on the calculation of predicted MOF surface area values from first principles. A method of modeling hydrolysis on MOF materials that correlates with experimental data was developed and refined. Complimentary experimental data were recorded via utilization of a combinatorial chemistry heat treatment unit and high-throughput X-ray diffractometer. The three main Deliverables for the project, namely (a) a MOF for pre-combustion (e.g., IGCC) CO{sub 2} capture, (b) a MOF for post-combustion (flue gas) CO{sub 2} capture, and (c) an assessment of commercial potential for a MOF in the IGCC application, were completed. The key properties for MOFs to work in this application - high CO{sub 2} capacity, good adsorption/desorption rates, high adsorption selectivity for CO{sub 2} over other gases such as methane and nitrogen, high stability to contaminants, namely

  16. Giant negative linear compression positively coupled to massive thermal expansion in a metal-organic framework.

    PubMed

    Cai, Weizhao; Katrusiak, Andrzej

    2014-07-04

    Materials with negative linear compressibility are sought for various technological applications. Such effects were reported mainly in framework materials. When heated, they typically contract in the same direction of negative linear compression. Here we show that this common inverse relationship rule does not apply to a three-dimensional metal-organic framework crystal, [Ag(ethylenediamine)]NO3. In this material, the direction of the largest intrinsic negative linear compression yet observed in metal-organic frameworks coincides with the strongest positive thermal expansion. In the perpendicular direction, the large linear negative thermal expansion and the strongest crystal compressibility are collinear. This seemingly irrational positive relationship of temperature and pressure effects is explained and the mechanism of coupling of compressibility with expansivity is presented. The positive coupling between compression and thermal expansion in this material enhances its piezo-mechanical response in adiabatic process, which may be used for designing new artificial composites and ultrasensitive measuring devices.

  17. Impregnated Metal-Organic Frameworks for the Removal of Toxic Industrial Chemicals

    DTIC Science & Technology

    2008-11-01

    on a nanotechnology approach to sorbent development for air purification applications. Metal-organic frameworks ( MOFs ) are a novel class of materials...that allow for specific functionalities to be designed directly into a porous framework. This report summarizes the evaluation of MOFs impregnated...with various chemicals for enhanced reactivity. Specifically, MOF -5 (IRMOF-l) was impregnated with citric acid, copper acetate, copper oxide, and

  18. Porous molybdenum carbide nano-octahedrons synthesized via confined carburization in metal-organic frameworks for efficient hydrogen production

    PubMed Central

    Wu, Hao Bin; Xia, Bao Yu; Yu, Le; Yu, Xin-Yao; Lou, Xiong Wen (David)

    2015-01-01

    Electrochemical water splitting has been considered as a promising approach to produce clean and sustainable hydrogen fuel. However, the lack of high-performance and low-cost electrocatalysts for hydrogen evolution reaction hinders the large-scale application. As a new class of porous materials with tunable structure and composition, metal-organic frameworks have been considered as promising candidates to synthesize various functional materials. Here we demonstrate a metal-organic frameworks-assisted strategy for synthesizing nanostructured transition metal carbides based on the confined carburization in metal-organic frameworks matrix. Starting from a compound consisting of copper-based metal-organic frameworks host and molybdenum-based polyoxometalates guest, mesoporous molybdenum carbide nano-octahedrons composed of ultrafine nanocrystallites are successfully prepared as a proof of concept, which exhibit remarkable electrocatalytic performance for hydrogen production from both acidic and basic solutions. The present study provides some guidelines for the design and synthesis of nanostructured electrocatalysts. PMID:25758159

  19. Interplay between defects, disorder and flexibility in metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Bennett, Thomas D.; Cheetham, Anthony K.; Fuchs, Alain H.; Coudert, François-Xavier

    2017-01-01

    Metal-organic frameworks are a novel family of chemically diverse materials, which are of interest across engineering, physics, chemistry, biology and medicine-based disciplines. Since the development of the field in its current form more than two decades ago, priority has been placed on the synthesis of new structures. However, more recently, a clear trend has emerged in shifting the emphasis from material design to exploring the chemical and physical properties of structures already known. In particular, although such nanoporous materials were traditionally seen as rigid crystalline structures, there is growing evidence that large-scale flexibility, the presence of defects and long-range disorder are not the exception in metal-organic frameworks, but the rule. Here we offer some perspective into how these concepts are perhaps inescapably intertwined, highlight recent advances in our understanding and discuss how a consideration of the interfaces between them may lead to enhancements of the materials' functionalities.

  20. Microporous metal-organic frameworks for storage and separation of small hydrocarbons.

    PubMed

    He, Yabing; Zhou, Wei; Krishna, Rajamani; Chen, Banglin

    2012-12-18

    Hydrocarbons are very important energy resources and raw materials for some industrially important products and fine chemicals. There is a need for the discovery of better materials that offer enhanced capacities for safe storage of hydrocarbons. Furthermore, the development of improved separation technologies will lead to significant reduction in energy requirements and costs. In this feature article, we provide an overview of the current status of the emerging microporous metal-organic frameworks for the storage and separation of small hydrocarbons.

  1. Three-Dimensional Hierarchical Architectures Derived from Surface-Mounted Metal-Organic Framework Membranes for Enhanced Electrocatalysis.

    PubMed

    Jia, Gan; Zhang, Wen; Fan, Guozheng; Li, Zhaosheng; Fu, Degang; Hao, Weichang; Yuan, Chunwei; Zou, Zhigang

    2017-09-04

    Inspired by the rapid development of metal-organic-framework-derived materials in various applications, a facile synthetic strategy was developed for fabrication of 3D hierarchical nanoarchitectures. A surface-mounted metal-organic framework membrane was pyrolyzed at a range of temperatures to produce catalysts with excellent trifunctional electrocatalytic efficiencies for the oxygen reduction, hydrogen evolution, and oxygen evolution reactions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Postsynthetic Tuning of Metal-Organic Frameworks for Targeted Applications.

    PubMed

    Islamoglu, Timur; Goswami, Subhadip; Li, Zhanyong; Howarth, Ashlee J; Farha, Omar K; Hupp, Joseph T

    2017-04-18

    Metal-organic frameworks (MOFs) are periodic, hybrid, atomically well-defined porous materials that typically form by self-assembly and consist of inorganic nodes (metal ions or clusters) and multitopic organic linkers. MOFs as a whole offer many intriguing properties, including ultrahigh porosity, tunable chemical functionality, and low density. These properties point to numerous potential applications, including gas storage, chemical separations, catalysis, light harvesting, and chemical sensing, to name a few. Reticular chemistry, or the linking of molecular building blocks into predetermined network structures, has been employed to synthesize thousands of MOFs. Given the vast library of candidate nodes and linkers, the number of potentially synthetically accessible MOFs is enormous. Nevertheless, a powerful complementary approach to obtain specific structures with desired chemical functionality is to modify known MOFs after synthesis. This approach is particularly useful when incorporation of particular chemical functionalities via direct synthesis is challenging or impossible. The challenges may stem from limited stability or solubility of precursors, unwanted secondary reactivity of precursors, or incompatibility of functional groups with the conditions needed for direct synthesis. MOFs can be postsynthetically modified by replacing the metal nodes and/or organic linkers or via functionalization of the metal nodes and/or organic linkers. Here we describe some of our efforts toward the development and application of postsynthetic strategies for imparting desired chemical functionalities in MOFs of known topology. The techniques include methods for functionalizing MOF nodes, i.e., solvent-assisted ligand incorporation (SALI) and atomic layer deposition in MOFs (AIM) as well as a method to replace structural linkers, termed solvent-assisted linker exchange (SALE), also known as postsynthethic exchange (PSE). For each functionalization strategy, we first describe

  3. Microporous metal-organic framework with potential for carbon dioxide capture at ambient conditions.

    PubMed

    Xiang, Shengchang; He, Yabing; Zhang, Zhangjing; Wu, Hui; Zhou, Wei; Krishna, Rajamani; Chen, Banglin

    2012-07-17

    Carbon dioxide capture and separation are important industrial processes that allow the use of carbon dioxide for the production of a range of chemical products and materials, and to minimize the effects of carbon dioxide emission. Porous metal-organic frameworks are promising materials to achieve such separations and to replace current technologies, which use aqueous solvents to chemically absorb carbon dioxide. Here we show that a metal-organic frameworks (UTSA-16) displays high uptake (160 cm(3) cm(-3)) of CO(2) at ambient conditions, making it a potentially useful adsorbent material for post-combustion carbon dioxide capture and biogas stream purification. This has been further confirmed by simulated breakthrough experiments. The high storage capacities and selectivities of UTSA-16 for carbon dioxide capture are attributed to the optimal pore cages and the strong binding sites to carbon dioxide, which have been demonstrated by neutron diffraction studies.

  4. Superexchange Charge Transport in Loaded Metal Organic Frameworks.

    PubMed

    Neumann, Tobias; Liu, Jianxi; Wächter, Tobias; Friederich, Pascal; Symalla, Franz; Welle, Alexander; Mugnaini, Veronica; Meded, Velimir; Zharnikov, Michael; Wöll, Christof; Wenzel, Wolfgang

    2016-07-26

    In the past, nanoporous metal-organic frameworks (MOFs) have been mostly studied for their huge potential with regard to gas storage and separation. More recently, the discovery that the electrical conductivity of a widely studied, highly insulating MOF, HKUST-1, improves dramatically when loaded with guest molecules has triggered a huge interest in the charge carrier transport properties of MOFs. The observed high conductivity, however, is difficult to reconcile with conventional transport mechanisms: neither simple hopping nor band transport models are consistent with the available experimental data. Here, we combine theoretical results and new experimental data to demonstrate that the observed conductivity can be explained by an extended hopping transport model including virtual hops through localized MOF states or molecular superexchange. Predictions of this model agree well with precise conductivity measurements, where experimental artifacts and the influence of defects are largely avoided by using well-defined samples and the Hg-drop junction approach.

  5. Recent progress in the synthesis of metal-organic frameworks.

    PubMed

    Sun, Yujia; Zhou, Hong-Cai

    2015-10-01

    Metal-organic frameworks (MOFs) have attracted considerable attention for various applications due to their tunable structure, porosity and functionality. In general, MOFs have been synthesized from isolated metal ions and organic linkers under hydrothermal or solvothermal conditions via one-spot reactions. The emerging precursor approach and kinetically tuned dimensional augmentation strategy add more diversity to this field. In addition, to speed up the crystallization process and create uniform crystals with reduced size, many alternative synthesis routes have been explored. Recent advances in microwave-assisted synthesis and electrochemical synthesis are presented in this review. In recent years, post-synthetic approaches have been shown to be powerful tools to synthesize MOFs with modified functionality, which cannot be attained via de novo synthesis. In this review, some current accomplishments of post-synthetic modification (PSM) based on covalent transformations and coordinative interactions as well as post-synthetic exchange (PSE) in robust MOFs are provided.

  6. Storage of electrical information in metal-organic-framework memristors.

    PubMed

    Yoon, Seok Min; Warren, Scott C; Grzybowski, Bartosz A

    2014-04-22

    Single crystals of a cyclodextrin-based metal-organic framework (MOF) infused with an ionic electrolyte and flanked by silver electrodes act as memristors. They can be electrically switched between low and high conductivity states that persist even in the absence of an applied voltage. In this way, these small blocks of nanoporous sugar function as a non-volatile RRAM memory elements that can be repeatedly read, erased, and re-written. These properties derive from ionic current within the MOF and the deposition of nanometer-thin passivating layers at the anode flanking the MOF crystal. The observed phenomena are crucially dependent on the sub-nanometer widths of the channels in the MOF, allowing the passage of only smaller ions. Conversely, with the electrolyte present but no MOF, there are no memristance or memory effects. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Chemical, thermal and mechanical stabilities of metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Howarth, Ashlee J.; Liu, Yangyang; Li, Peng; Li, Zhanyong; Wang, Timothy C.; Hupp, Joseph T.; Farha, Omar K.

    2016-03-01

    The construction of thousands of well-defined, porous, metal-organic framework (MOF) structures, spanning a broad range of topologies and an even broader range of pore sizes and chemical functionalities, has fuelled the exploration of many applications. Accompanying this applied focus has been a recognition of the need to engender MOFs with mechanical, thermal and/or chemical stability. Chemical stability in acidic, basic and neutral aqueous solutions is important. Advances over recent years have made it possible to design MOFs that possess different combinations of mechanical, thermal and chemical stability. Here, we review these advances and the associated design principles and synthesis strategies. We focus on how these advances may render MOFs effective as heterogeneous catalysts, both in chemically harsh condensed phases and in thermally challenging conditions relevant to gas-phase reactions. Finally, we briefly discuss future directions of study for the production of highly stable MOFs.

  8. Metal-organic frameworks for artificial photosynthesis and photocatalysis.

    PubMed

    Zhang, Teng; Lin, Wenbin

    2014-08-21

    Solar energy is an alternative, sustainable energy source for mankind. Finding a convenient way to convert sunlight energy into chemical energy is a key step towards realizing large-scale solar energy utilization. Owing to their structural regularity and synthetic tunability, metal-organic frameworks (MOFs) provide an interesting platform to hierarchically organize light-harvesting antennae and catalytic centers to achieve solar energy conversion. Such photo-driven catalytic processes not only play a critical role in the solar to chemical energy conversion scheme, but also provide a novel methodology for the synthesis of fine chemicals. In this review, we summarize the fundamental principles of energy transfer and photocatalysis and provide an overview of the latest progress in energy transfer, light-harvesting, photocatalytic proton and CO2 reduction, and water oxidation using MOFs. The applications of MOFs in organic photocatalysis and degradation of model organic pollutants are also discussed.

  9. Transformation of metal-organic frameworks for molecular sieving membranes

    PubMed Central

    Li, Wanbin; Zhang, Yufan; Zhang, Congyang; Meng, Qin; Xu, Zehai; Su, Pengcheng; Li, Qingbiao; Shen, Chong; Fan, Zheng; Qin, Lei; Zhang, Guoliang

    2016-01-01

    The development of simple, versatile strategies for the synthesis of metal-organic framework (MOF)-derived membranes are of increasing scientific interest, but challenges exist in understanding suitable fabrication mechanisms. Here we report a route for the complete transformation of a series of MOF membranes and particles, based on multivalent cation substitution. Through our approach, the effective pore size can be reduced through the immobilization of metal salt residues in the cavities, and appropriate MOF crystal facets can be exposed, to achieve competitive molecular sieving capabilities. The method can also be used more generally for the synthesis of a variety of MOF membranes and particles. Importantly, we design and synthesize promising MOF membranes candidates that are hard to achieve through conventional methods. For example, our CuBTC/MIL-100 membrane exhibits 89, 171, 241 and 336 times higher H2 permeance than that of CO2, O2, N2 and CH4, respectively. PMID:27090597

  10. Coordinative alignment of molecules in chiral metal-organic frameworks.

    PubMed

    Lee, Seungkyu; Kapustin, Eugene A; Yaghi, Omar M

    2016-08-19

    A chiral metal-organic framework, MOF-520, was used to coordinatively bind and align molecules of varying size, complexity, and functionality. The reduced motional degrees of freedom obtained with this coordinative alignment method allowed the structures of molecules to be determined by single-crystal x-ray diffraction techniques. The chirality of the MOF backbone also served as a reference in the structure solution for an unambiguous assignment of the absolute configuration of bound molecules. Sixteen molecules representing four common functional groups (primary alcohol, phenol, vicinal diol, and carboxylic acid), ranging in complexity from methanol to plant hormones (gibberellins, containing eight stereocenters), were crystallized and had their precise structure determined. We distinguished single and double bonds in gibberellins, and we enantioselectively crystallized racemic jasmonic acid, whose absolute configuration had only been inferred from derivatives.

  11. Metal-Organic Frameworks as Catalysts for Oxidation Reactions.

    PubMed

    Dhakshinamoorthy, Amarajothi; Asiri, Abdullah M; Garcia, Hermenegildo

    2016-06-06

    This Concept is aimed at describing the current state of the art in metal-organic frameworks (MOFs) as heterogeneous catalysts for liquid-phase oxidations, focusing on three important substrates, namely, alkenes, alkanes and alcohols. Emphases are on the nature of active sites that have been incorporated within MOFs and on future targets to be set in this area. Thus, selective alkene epoxidation with peroxides or oxygen catalyzed by constitutional metal nodes of MOFs as active sites are still to be developed. Moreover, no noble metal-free MOF has been reported to date that can act as a general catalyst for the aerobic oxidation of primary and secondary aliphatic alcohols. In contrast, in the case of alkanes, a target should be to tune the polarity of MOF internal pores to control the outcome of the autooxidation process, resulting in the selective formation of alcohol/ketone mixtures at high conversion.

  12. Transformation of metal-organic frameworks for molecular sieving membranes

    NASA Astrophysics Data System (ADS)

    Li, Wanbin; Zhang, Yufan; Zhang, Congyang; Meng, Qin; Xu, Zehai; Su, Pengcheng; Li, Qingbiao; Shen, Chong; Fan, Zheng; Qin, Lei; Zhang, Guoliang

    2016-04-01

    The development of simple, versatile strategies for the synthesis of metal-organic framework (MOF)-derived membranes are of increasing scientific interest, but challenges exist in understanding suitable fabrication mechanisms. Here we report a route for the complete transformation of a series of MOF membranes and particles, based on multivalent cation substitution. Through our approach, the effective pore size can be reduced through the immobilization of metal salt residues in the cavities, and appropriate MOF crystal facets can be exposed, to achieve competitive molecular sieving capabilities. The method can also be used more generally for the synthesis of a variety of MOF membranes and particles. Importantly, we design and synthesize promising MOF membranes candidates that are hard to achieve through conventional methods. For example, our CuBTC/MIL-100 membrane exhibits 89, 171, 241 and 336 times higher H2 permeance than that of CO2, O2, N2 and CH4, respectively.

  13. Metal-Organic Frameworks for CO2 Chemical Transformations.

    PubMed

    He, Hongming; Perman, Jason A; Zhu, Guangshan; Ma, Shengqian

    2016-12-01

    Carbon dioxide (CO2 ), as the primary greenhouse gas in the atmosphere, triggers a series of environmental and energy related problems in the world. Therefore, there is an urgent need to develop multiple methods to capture and convert CO2 into useful chemical products, which can significantly improve the environment and promote sustainable development. Over the past several decades, metal-organic frameworks (MOFs) have shown outstanding heterogeneous catalytic activity due in part to their high internal surface area and chemical functionalities. These properties and the ability to synthesize MOF platforms allow experiments to test structure-function relationships for transforming CO2 into useful chemicals. Herein, recent developments are highlighted for MOFs participating as catalysts for the chemical fixation and photochemical reduction of CO2 . Finally, opportunities and challenges facing MOF catalysts are discussed in this ongoing research area.

  14. Recent progress in the synthesis of metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Sun, Yujia; Zhou, Hong-Cai

    2015-10-01

    Metal-organic frameworks (MOFs) have attracted considerable attention for various applications due to their tunable structure, porosity and functionality. In general, MOFs have been synthesized from isolated metal ions and organic linkers under hydrothermal or solvothermal conditions via one-spot reactions. The emerging precursor approach and kinetically tuned dimensional augmentation strategy add more diversity to this field. In addition, to speed up the crystallization process and create uniform crystals with reduced size, many alternative synthesis routes have been explored. Recent advances in microwave-assisted synthesis and electrochemical synthesis are presented in this review. In recent years, post-synthetic approaches have been shown to be powerful tools to synthesize MOFs with modified functionality, which cannot be attained via de novo synthesis. In this review, some current accomplishments of post-synthetic modification (PSM) based on covalent transformations and coordinative interactions as well as post-synthetic exchange (PSE) in robust MOFs are provided.

  15. Selective sulfur dioxide adsorption on crystal defect sites on an isoreticular metal organic framework series

    PubMed Central

    Rodríguez-Albelo, L. Marleny; López-Maya, Elena; Hamad, Said; Ruiz-Salvador, A. Rabdel; Calero, Sofia; Navarro, Jorge A.R.

    2017-01-01

    The widespread emissions of toxic gases from fossil fuel combustion represent major welfare risks. Here we report the improvement of the selective sulfur dioxide capture from flue gas emissions of isoreticular nickel pyrazolate metal organic frameworks through the sequential introduction of missing-linker defects and extra-framework barium cations. The results and feasibility of the defect pore engineering carried out are quantified through a combination of dynamic adsorption experiments, X-ray diffraction, electron microscopy and density functional theory calculations. The increased sulfur dioxide adsorption capacities and energies as well as the sulfur dioxide/carbon dioxide partition coefficients values of defective materials compared to original non-defective ones are related to the missing linkers enhanced pore accessibility and to the specificity of sulfur dioxide interactions with crystal defect sites. The selective sulfur dioxide adsorption on defects indicates the potential of fine-tuning the functional properties of metal organic frameworks through the deliberate creation of defects. PMID:28198376

  16. Selective sulfur dioxide adsorption on crystal defect sites on an isoreticular metal organic framework series

    NASA Astrophysics Data System (ADS)

    Rodríguez-Albelo, L. Marleny; López-Maya, Elena; Hamad, Said; Ruiz-Salvador, A. Rabdel; Calero, Sofia; Navarro, Jorge A. R.

    2017-02-01

    The widespread emissions of toxic gases from fossil fuel combustion represent major welfare risks. Here we report the improvement of the selective sulfur dioxide capture from flue gas emissions of isoreticular nickel pyrazolate metal organic frameworks through the sequential introduction of missing-linker defects and extra-framework barium cations. The results and feasibility of the defect pore engineering carried out are quantified through a combination of dynamic adsorption experiments, X-ray diffraction, electron microscopy and density functional theory calculations. The increased sulfur dioxide adsorption capacities and energies as well as the sulfur dioxide/carbon dioxide partition coefficients values of defective materials compared to original non-defective ones are related to the missing linkers enhanced pore accessibility and to the specificity of sulfur dioxide interactions with crystal defect sites. The selective sulfur dioxide adsorption on defects indicates the potential of fine-tuning the functional properties of metal organic frameworks through the deliberate creation of defects.

  17. Selective sulfur dioxide adsorption on crystal defect sites on an isoreticular metal organic framework series.

    PubMed

    Rodríguez-Albelo, L Marleny; López-Maya, Elena; Hamad, Said; Ruiz-Salvador, A Rabdel; Calero, Sofia; Navarro, Jorge A R

    2017-02-15

    The widespread emissions of toxic gases from fossil fuel combustion represent major welfare risks. Here we report the improvement of the selective sulfur dioxide capture from flue gas emissions of isoreticular nickel pyrazolate metal organic frameworks through the sequential introduction of missing-linker defects and extra-framework barium cations. The results and feasibility of the defect pore engineering carried out are quantified through a combination of dynamic adsorption experiments, X-ray diffraction, electron microscopy and density functional theory calculations. The increased sulfur dioxide adsorption capacities and energies as well as the sulfur dioxide/carbon dioxide partition coefficients values of defective materials compared to original non-defective ones are related to the missing linkers enhanced pore accessibility and to the specificity of sulfur dioxide interactions with crystal defect sites. The selective sulfur dioxide adsorption on defects indicates the potential of fine-tuning the functional properties of metal organic frameworks through the deliberate creation of defects.

  18. Metal-Organic Framework-Based Nanomedicine Platforms for Drug Delivery and Molecular Imaging.

    PubMed

    Cai, Wen; Chu, Cheng-Chao; Liu, Gang; Wáng, Yì-Xiáng J

    2015-10-07

    Metal-organic frameworks (MOFs), which are a unique class of hybrid porous materials built from metal ions and organic linkers, have attracted significant research interest in recent years. Compared with conventional porous materials, MOFs exhibit a variety of advantages, including a large surface area, a tunable pore size and shape, an adjustable composition and structure, biodegradability, and versatile functionalities, which enable MOFs to perform as promising platforms for drug delivery, molecular imaging, and theranostic applications. In this article, the recent research progress related to nanoscale metal-organic frameworks (NMOFs) is summarized with a focus on synthesis strategies and drug delivery, molecular imaging, and theranostic applications. The future challenges and opportunities of NMOFs are also discussed in the context of translational medical research. More effort is warranted to develop clinically translatable NMOFs for various applications in nanomedicine.

  19. Metal-organic frameworks for the removal of toxic industrial chemicals and chemical warfare agents.

    PubMed

    Bobbitt, N Scott; Mendonca, Matthew L; Howarth, Ashlee J; Islamoglu, Timur; Hupp, Joseph T; Farha, Omar K; Snurr, Randall Q

    2017-06-06

    Owing to the vast diversity of linkers, nodes, and topologies, metal-organic frameworks can be tailored for specific tasks, such as chemical separations or catalysis. Accordingly, these materials have attracted significant interest for capture and/or detoxification of toxic industrial chemicals and chemical warfare agents. In this paper, we review recent experimental and computational work pertaining to the capture of several industrially-relevant toxic chemicals, including NH3, SO2, NO2, H2S, and some volatile organic compounds, with particular emphasis on the challenging issue of designing materials that selectively adsorb these chemicals in the presence of water. We also examine recent research on the capture and catalytic degradation of chemical warfare agents such as sarin and sulfur mustard using metal-organic frameworks.

  20. Collaborative interactions to enhance gas binding energy in porous metal-organic frameworks.

    PubMed

    Lin, Rui-Biao; Chen, Banglin

    2017-03-01

    Metal-organic frameworks (MOFs) are potentially useful materials for hydrogen and methane storage. However, the weak interactions between the MOF host and gas guest molecules have limited their storage capacities at elevated temperatures. In this issue, Alkordi et al. [IUCrJ (2017), 4, 131-135] illustrate an example of a porous MOF with a suitable pore size and unique pore surface for enhanced interaction with hydrogen molecules, providing the promise of further increasing the gas binding affinity through collaborative interactions.

  1. Van der Waals density functional study of water binding in metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Lee, Kyuho; Smit, Berend; Neaton, Jeffrey B.

    2013-03-01

    Metal-organic frameworks (MOFs) are promising candidate materials for gas storage, gas separation and catalysis. However, MOFs are vulnerable to humid air and effective surface area drops dramatically on an exposure to water. In this theoretical study, we investigate the interaction of single water molecule with MOF-74 on different binding sites by using van der Waals density functionals. We also explore how different type of metal cations affect the interaction.

  2. One-pot synthesis of protein-embedded metal-organic frameworks with enhanced biological activities.

    PubMed

    Lyu, Fengjiao; Zhang, Yifei; Zare, Richard N; Ge, Jun; Liu, Zheng

    2014-10-08

    Protein molecules were directly embedded in metal-organic frameworks (MOFs) by a coprecipitation method. The protein molecules majorly embedded on the surface region of MOFs display high biological activities. As a demonstration of the power of such materials, the resulting Cyt c embedded in ZIF-8 showed a 10-fold increase in peroxidase activity compared to free Cyt c in solution and thus gave convenient, fast, and highly sensitive detection of trace amounts of explosive organic peroxides in solution.

  3. Metal-organic framework templated inorganic sorbents for rapid and efficient extraction of heavy metals.

    PubMed

    Abney, C W; Gilhula, J C; Lu, K; Lin, W

    2014-12-17

    An innovative wet-treatment with Na2 S transforms two indium metal-organic frameworks (MOFs) into a series of porous inorganic sorbents. These MOF-templated materials display remarkable affinity for heavy metals with saturation occurring in less than 1 h. The saturation capacity for Hg(II) exceeds 2 g g(-1) , more than doubling the best thiol-functionalized sorbents in the literature.

  4. Combining UV lithography and an imprinting technique for patterning metal-organic frameworks.

    PubMed

    Doherty, Cara M; Grenci, Gianluca; Riccò, Raffaele; Mardel, James I; Reboul, Julien; Furukawa, Shuhei; Kitagawa, Susumu; Hill, Anita J; Falcaro, Paolo

    2013-09-14

    Thin metal-organic framework (MOF) films are patterned using UV lithography and an imprinting technique. A UV lithographed SU-8 film is imprinted onto a film of MOF powder forming a 2D MOF patterned film. This straightforward method can be applied to most MOF materials, is versatile, cheap, and potentially useful for commercial applications such as lab-on-a-chip type devices. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Stable Metal-Organic Frameworks Containing Single-Molecule Traps for Enzyme Encapsulation

    DTIC Science & Technology

    2015-01-19

    operational stability and difficulty of reuse . Here, we develop a series of stable metal-organic frameworks with rationally designed ultra-large...10.1038/ncomms6979 1 Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, USA. 2 Berzelii Centre EXSELENT on Porous...P. R. China. 4 Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77842, USA. * These authors contributed

  6. Phosphine Gas Adsorption in a Series of Metal-Organic Frameworks.

    PubMed

    Weston, Mitchell H; Morris, William; Siu, Paul W; Hoover, William J; Cho, David; Richardson, Rachelle K; Farha, Omar K

    2015-09-08

    For the first time, phosphine adsorption has been evaluated in a series of metal-organic frameworks (MOFs). Open-metal coordination sites were found to significantly enhance the ability of MOFs to adsorb highly toxic phosphine gas, with the identity of the open-metal site also modulating the amount of gas adsorbed. The MOFs studied outperform activated carbon, a commonly used material to capture phosphine.

  7. A high rotational barrier for physisorbed hydrogen in an fcu-metal-organic framework.

    PubMed

    Pham, Tony; Forrest, Katherine A; Georgiev, Peter A; Lohstroh, Wiebke; Xue, Dong-Xu; Hogan, Adam; Eddaoudi, Mohamed; Space, Brian; Eckert, Juergen

    2014-11-25

    A combined inelastic neutron scattering (INS) and theoretical study of H2 sorption in Y-FTZB, a recently reported metal-organic framework (MOF) with fcu topology, reveals that the strongest binding site in the MOF causes a high barrier to rotation on the sorbed H2. This rotational barrier for H2 is the highest yet of reported MOF materials based on physisorption.

  8. Application of metal-organic frameworks for purification of vegetable oils.

    PubMed

    Vlasova, E A; Yakimov, S A; Naidenko, E V; Kudrik, E V; Makarov, S V

    2016-01-01

    Reported here is the synthesis of aluminum-, zinc- and titanium-containing metal-organic frameworks based on terephthalic acid and an investigation on the possibility of using these compounds as adsorbents for the purification of unrefined vegetable oils. It is found that aluminum-, zinc- and titanium-containing metal-organic frameworks improve the physicochemical properties of unrefined vegetable oils (more pleasant taste and odor) due to the binding of free fatty acids and peroxide compounds. It is established that the synthesized materials are more effective in these respects as compared with traditional adsorbents. An adsorption mechanism of free fatty acids and peroxides is proposed. Last but not least, the used MOF can be easily recycled at least five times, via solvent washing.

  9. Metal-organic frameworks: structure, properties, methods of synthesis and characterization

    NASA Astrophysics Data System (ADS)

    Butova, V. V.; Soldatov, M. A.; Guda, A. A.; Lomachenko, K. A.; Lamberti, C.

    2016-03-01

    This review deals with key methods of synthesis and characterization of metal-organic frameworks (MOFs). The modular structure affords a wide variety of MOFs with different active metal sites and organic linkers. These compounds represent a new stage of development of porous materials in which the pore size and the active site structure can be modified within wide limits. The set of experimental methods considered in this review is sufficient for studying the short-range and long-range order of the MOF crystal structure, determining the morphology of samples and elucidating the processes that occur at the active metal site in the course of chemical reactions. The interest in metal-organic frameworks results, first of all, from their numerous possible applications, ranging from gas separation and storage to chemical reactions within the pores. The bibliography includes 362 references.

  10. Molecular dynamics simulations of gas diffusion in metal-organic frameworks: argon in CuBTC.

    PubMed

    Skoulidas, Anastasios I

    2004-02-11

    The class of coordination polymers known as metal-organic frameworks (MOFs) has three-dimensional porous structures that are considered as a promising alternative to zeolites and other nanoporous materials for catalysis, gas adsorption, and gas separation applications. In this paper, we present the first study of gas diffusion inside an MOF and compare the observed diffusion to known behaviors in zeolites. Using grand canonical Monte Carlo and equilibrium molecular dynamics, we calculate the adsorption isotherm and self-, corrected, and transport diffusivities for argon in the CuBTC metal-organic framework. Our results indicate that diffusion of Ar in CuBTC is very similar to Ar diffusion in silica zeolites in magnitude, concentration, and temperature dependence. This conclusion appears to apply to a broad range of MOF structures.

  11. Evaluation of Metal-Organic Frameworks and Porous Polymer Networks for CO2 -Capture Applications.

    PubMed

    Verdegaal, Wolfgang M; Wang, Kecheng; Sculley, Julian P; Wriedt, Mario; Zhou, Hong-Cai

    2016-03-21

    This manuscript presents experimental data for 20 adsorption materials (metal-organic frameworks, porous polymer networks, and Zeolite-5A), including CO2 and N2 isotherms and heat capacities. With input from only experimental data, working capacities per energy for each material were calculated. Furthermore, by running seven different carbon-capture scenarios in which the initial flue-gas composition and process temperature was systematically changed, we present a range of performances for each material and quantify how sensitive each is to these varying parameters. The presented calculations provide researchers with a tool to investigate promising carbon-capture materials more easily and completely.

  12. Ultrathin metal-organic framework array for efficient electrocatalytic water splitting

    PubMed Central

    Duan, Jingjing; Chen, Sheng; Zhao, Chuan

    2017-01-01

    Two-dimensional metal-organic frameworks represent a family of materials with attractive chemical and structural properties, which are usually prepared in the form of bulk powders. Here we show a generic approach to fabricate ultrathin nanosheet array of metal-organic frameworks on different substrates through a dissolution–crystallization mechanism. These materials exhibit intriguing properties for electrocatalysis including highly exposed active molecular metal sites owning to ultra-small thickness of nanosheets, improved electrical conductivity and a combination of hierarchical porosity. We fabricate a nickel-iron-based metal-organic framework array, which demonstrates superior electrocatalytic performance towards oxygen evolution reaction with a small overpotential of 240 mV at 10 mA cm−2, and robust operation for 20,000 s with no detectable activity decay. Remarkably, the turnover frequency of the electrode is 3.8 s−1 at an overpotential of 400 mV. We further demonstrate the promise of these electrodes for other important catalytic reactions including hydrogen evolution reaction and overall water splitting. PMID:28580963

  13. Ultrathin metal-organic framework array for efficient electrocatalytic water splitting

    NASA Astrophysics Data System (ADS)

    Duan, Jingjing; Chen, Sheng; Zhao, Chuan

    2017-06-01

    Two-dimensional metal-organic frameworks represent a family of materials with attractive chemical and structural properties, which are usually prepared in the form of bulk powders. Here we show a generic approach to fabricate ultrathin nanosheet array of metal-organic frameworks on different substrates through a dissolution-crystallization mechanism. These materials exhibit intriguing properties for electrocatalysis including highly exposed active molecular metal sites owning to ultra-small thickness of nanosheets, improved electrical conductivity and a combination of hierarchical porosity. We fabricate a nickel-iron-based metal-organic framework array, which demonstrates superior electrocatalytic performance towards oxygen evolution reaction with a small overpotential of 240 mV at 10 mA cm-2, and robust operation for 20,000 s with no detectable activity decay. Remarkably, the turnover frequency of the electrode is 3.8 s-1 at an overpotential of 400 mV. We further demonstrate the promise of these electrodes for other important catalytic reactions including hydrogen evolution reaction and overall water splitting.

  14. Spectroscopic Evidence for Room Temperature Interaction of Molecular Oxygen with Cobalt Porphyrin Linker Sites within a Metal-Organic Framework.

    PubMed

    Lahanas, Nicole; Kucheryavy, Pavel; Lockard, Jenny V

    2016-10-17

    Metalloporphyrin-based metal-organic frameworks offer a promising platform for developing solid-state porous materials with accessible, coordinatively unsaturated metal sites. Probing small-molecule interactions at the metalloporphyrin sites within these materials on a molecular level under ambient conditions is crucial for both understanding and ultimately harnessing this functionality for potential catalytic purposes. Co-PCN-222, a metal-organic framework based on cobalt(II) porphyrin linkers. is investigated using in situ UV-vis diffuse-reflectance and X-ray absorption spectroscopy. Spectroscopic evidence for the axial interaction of diatomic oxygen with the framework's open metalloporphyrin sites at room temperature is presented and discussed.

  15. Anisotropic thermal expansion in a metal-organic framework.

    PubMed

    Madsen, Solveig Røgild; Lock, Nina; Overgaard, Jacob; Iversen, Bo Brummerstedt

    2014-06-01

    Ionothermal reaction between Mn(II)(acetate)2·4H2O and 1,3,5-benzenetricarboxylic acid (H3BTC) in either of the two ionic liquids 1-ethyl-3-methylimidazolium bromide (EMIMBr) and 1-ethyl-3-methylimidazolium tosylate (EMIMOTs) resulted in the formation of the new metal-organic framework (MOF) EMIM[Mn(II)BTC] (BTC = 1,3,5-benzenetricarboxylate). The compound crystallizes in the orthorhombic space group Pbca with unit-cell parameters of a = 14.66658 (12), b = 12.39497 (9), c = 16.63509 (14) Å at 100 K. Multi-temperature single-crystal (15-340 K) and powder X-ray diffraction studies (100-400 K) reveal strongly anisotropic thermal expansion properties. The linear thermal expansion coefficients, αL(l), attain maximum values at 400 K along the a- and b-axis, with αL(a) = 115 × 10(-6) K(-1) and αL(b) = 75 × 10(-6) K(-1). At 400 K a negative thermal expansion coefficient of -40 × 10(-6) K(-1) is observed along the c-axis. The thermal expansion is coupled to a continuous deformation of the framework, which causes the structure to expand in two directions. Due to the rigidity of the linker, the expansion in the ab plane causes the network to contract along the c-axis. Hirshfeld surface analysis has been used to describe the interaction between the framework structure and the EMIM cation that resides within the channel. This reveals a number of rather weak interactions and one governing hydrogen-bonding interactions.

  16. Nanoporous metal oxides with tunable and nanocrystalline frameworks via conversion of metal-organic frameworks.

    PubMed

    Kim, Tae Kyung; Lee, Kyung Joo; Cheon, Jae Yeong; Lee, Jae Hwa; Joo, Sang Hoon; Moon, Hoi Ri

    2013-06-19

    Nanoporous metal oxide materials are ubiquitous in the material sciences because of their numerous potential applications in various areas, including adsorption, catalysis, energy conversion and storage, optoelectronics, and drug delivery. While synthetic strategies for the preparation of siliceous nanoporous materials are well-established, nonsiliceous metal oxide-based nanoporous materials still present challenges. Herein, we report a novel synthetic strategy that exploits a metal-organic framework (MOF)-driven, self-templated route toward nanoporous metal oxides via thermolysis under inert atmosphere. In this approach, an aliphatic ligand-based MOF is thermally converted to nanoporous metal oxides with highly nanocrystalline frameworks, in which aliphatic ligands act as the self-templates that are afterward evaporated to generate nanopores. We demonstrate this concept with hierarchically nanoporous magnesia (MgO) and ceria (CeO2), which have potential applicability for adsorption, catalysis, and energy storage. The pore size of these nanoporous metal oxides can be readily tuned by simple control of experimental parameters. Significantly, nanoporous MgO exhibits exceptional CO2 adsorption capacity (9.2 wt %) under conditions mimicking flue gas. This MOF-driven strategy can be expanded to other nanoporous monometallic and multimetallic oxides with a multitude of potential applications.

  17. Recent Advances in Carbon Capture with Metal-Organic Frameworks.

    PubMed

    Stylianou, Kyriakos C; Queen, Wendy L

    2015-01-01

    The escalating level of CO(2) in the atmosphere is one of the most critical environmental issues of our age. The carbon capture and storage from pilot test plants represents an option for reducing CO(2) emissions, however, the energy cost associated with post-combustion carbon capture process alone is ∼30% of the total energy generated by the power plant. Thus, the generation of carbon capture adsorbents with high uptake capacities, great separation performance and low cost is of paramount importance. Metal-organic frameworks are infinite networks of metal-containing nodes bridged by organic ligands through coordination bonds into porous extended structures and several reports have revealed that they are ideal candidates for the selective capture of CO(2). In this review we summarize recent advances related to the synthesis of porous MOFs and the latest strategies to enhance the CO(2) adsorption enthalpies and capacities at low-pressures, increase hydrolytic and mechanical stabilities, and improve the ease of regeneration. Although they show great promise for post-combustion carbon capture, there are still major challenges that must be overcome before they can be used for such a large-scale application.

  18. Infrared spectroscopy of trapped hydrogen in metal-organic-frameworks

    NASA Astrophysics Data System (ADS)

    Fitzgerald, Stephen; Allen, Kelty; Landerman, Patrick; Rowsell, Jesse

    2007-03-01

    We present a novel use of diffuse reflectance infrared spectroscopy to study the quantum dynamics of molecular hydrogen trapped within metal-organic-framework (MOF) hosts. This technique is particularly useful in the context of hydrogen storage since it provides detailed information about the intermolecular potential at the binding site. The spectra consist of quite sharp bands associated with the quantized vibrational and rotational motion of the trapped hydrogen. The vibrational bands are redshifted relative to the gas phase while the rotational sidebands contain an additional fine structure due to the orientational dependence of the binding potential. Results on MOF-5 reveal the presence of two primary binding sites. The first saturates at a loading concentration on the order of 4 H2 per Zn ion and has a binding energy of roughly 4 kJ/mole. The second has a somewhat lower binding energy. Both site produce an ortho to para conversion rate on the order of 30-50 % per hour.

  19. Xenon Recovery at Room Temperature using Metal-Organic Frameworks.

    PubMed

    Elsaidi, Sameh K; Ongari, Daniele; Xu, Wenqian; Mohamed, Mona H; Haranczyk, Maciej; Thallapally, Praveen K

    2017-08-10

    Xenon is known to be a very efficient anesthetic gas, but its cost prohibits the wider use in medical industry and other potential applications. It has been shown that Xe recovery and recycling from anesthetic gas mixtures can significantly reduce its cost as anesthetic. The current technology uses series of adsorbent columns followed by low-temperature distillation to recover Xe; this method is expensive to use in medical facilities. Herein, we propose a much simpler and more efficient system to recover and recycle Xe from exhaled anesthetic gas mixtures at room temperature using metal-organic frameworks (MOFs). Among the MOFs tested, PCN-12 exhibits unprecedented performance with high Xe capacity and Xe/O2 , Xe/N2 and Xe/CO2 selectivity at room temperature. The in situ synchrotron measurements suggest that Xe is occupies the small pockets of PCN-12 compared to unsaturated metal centers (UMCs). Computational modeling of adsorption further supports our experimental observation of Xe binding sites in PCN-12. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Controlled Growth of Metal-Organic Frameworks on Polymer Brushes.

    PubMed

    Hou, Liman; Zhou, Mingdong; Dong, Xiaozhe; Wang, Lei; Xie, Zhigang; Dong, Dewen; Zhang, Ning

    2017-08-17

    Polymer brushes are for the first time used to induce the synthesis of metal-organic frameworks (MOFs). The semi-fixed polymer chains provide a confined environment, which allows a mild growth of MOFs in between polymer chains to give surface-attached spherical MOF nanoparticles, in contrast to the larger MOF cubes/plates formed simultaneously in solution. Polymer brushes bearing carboxylate acid functionalities are indispensable for the formation of surface bound MOFs, while no MOF nanoparticles are observed on neutral polymer brushes. Characterization of the resultant MOF/polymer brushes hybrid film indicates the formation of crystalline MOF structure. The dimension of surface-attached MOFs can be fine-tuned from 20 nm to 1.4 μm simply by varying the structural parameter of polymer brushes and the nucleation duration. The method is not only applicable to the synthesis of MOF-5 and MIL-125, but shows great potential for the preparation of other surface-attached MOFs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Xenon Recovery at Room Temperature using Metal Organic Frameworks

    SciTech Connect

    Elsaidi, Sameh K.; Ongari, Daniele; Xu, Wenqian; Mohamed, Mona H.; Haranczyk, Maciej; Thallapally, Praveen K.

    2017-01-01

    Xenon is known to be a very efficient anesthetic gas but its cost prohibits the wider use in medical industry and other potential applications. It has been shown that Xe recovery and recycle from anesthetic gas mixture can significantly reduce its cost as anesthetic. The current technology uses series of adsorbent columns followed by low temperature distillation to recover Xe, which is expensive to use in medical facilities. Herein, we propose much efficient and simpler system to recover and recycle Xe from simulant exhale anesthetic gas mixture at room temperature using metal organic frameworks. Among the MOFs tested, PCN-12 exhibits unprecedented performance with high Xe capacity, Xe/O2, Xe/N2 and Xe/CO2 selectivity at room temperature. The in-situ synchrotron measurements suggest the Xe is occupied in the small pockets of PCN-12 compared to unsaturated metal centers (UMCs). Computational modeling of adsorption further supports our experimental observation of Xe binding sites in PCN-12.

  2. Monoenergetic Positronium Emission from Metal-Organic Framework Crystals

    NASA Astrophysics Data System (ADS)

    Jones, A. C. L.; Goldman, H. J.; Zhai, Q.; Feng, P.; Tom, H. W. K.; Mills, A. P.

    2015-04-01

    Recently it has been discovered that positronium (Ps), after forming in metal-organic framework (MOF) crystals, is emitted into vacuum with a high efficiency and low energy that can only be explained by its propagating as delocalized Bloch states. We show that the Ps atoms are emitted from MOFs in a series of narrow energy peaks consistent with Ps at Bloch-state energy minima being emitted adiabatically into the vacuum. This implies that the Ps emission energy spectra can be directly compared with calculations to obtain detailed information about the Ps band structure in the MOF crystal. The narrow energy width of the lowest energy Ps peak from one MOF sample (2-Methylimidazole zinc salt ZIF-8) suggests it originates from a polaronic Ps surface state. Other peaks can be assigned to Ps with an effective mass of about twice that of bare Ps. Given the immense catalog of available MOF crystals, it should be possible to tune the Ps properties to make vastly improved sources with high production efficiency and a narrow energy spread, for use in fundamental physics experiments.

  3. CO2-Selective Nanoporous Metal-Organic Framework Microcantilevers

    PubMed Central

    Yim, Changyong; Lee, Moonchan; Yun, Minhyuk; Kim, Gook-Hee; Kim, Kyong Tae; Jeon, Sangmin

    2015-01-01

    Nanoporous anodic aluminum oxide (AAO) microcantilevers are fabricated and MIL-53 (Al) metal-organic framework (MOF) layers are directly synthesized on each cantilever surface by using the aluminum oxide as the metal ion source. Exposure of the MIL53-AAO cantilevers to various concentrations of CO2, N2, CO, and Ar induces changes in their deflections and resonance frequencies. The results of the resonance frequency measurements for the different adsorbed gas molecules are almost identical when the frequency changes are normalized by the molecular weights of the gases. In contrast, the deflection measurements show that only CO2 adsorption induces substantial bending of the MIL53-AAO cantilevers. This selective deflection of the cantilevers is attributed to the strong interactions between CO2 and the hydroxyl groups in MIL-53, which induce structural changes in the MIL-53 layers. Simultaneous measurements of the resonance frequency and the deflection are performed to show that the diffusion of CO2 into the nanoporous MIL-53 layers occurs very rapidly, whereas the binding of CO2 to hydroxyl groups occurs relatively slowly, which indicates that the adsorption of CO2 onto the MIL-53 layers and the desorption of CO2 from the MIL-53 layers are reaction limited. PMID:26035805

  4. Doping of Metal-Organic Frameworks with Functional Guest Molecules and Nanoparticles

    NASA Astrophysics Data System (ADS)

    Schröder, Felicitas; Fischer, Roland A.

    Nanoparticle synthesis within metal-organic frameworks (MOFs) is performed by the adsorption of suitable precursor molecules for the metal component and subsequent decomposition to the composite materials nanoparticles@MOF. This chapter will review different approaches of loading MOFs with more complex organic molecules and metal-organic precursor molecules. The related reactions inside MOFs are discussed with a focus on stabilizing reactive intermediates in the corresponding cavities. The syntheses of metal and metal oxide nanoparticles inside MOFs are reviewed, and different synthetic routes compared. Emphasis is placed on the micro structural characterization of the materials nanoparticles@MOF with a particular focus on the location of embedded nanoparticles using TEM methods. Some first examples of applications of the doped MOFs in heterogeneous catalysis and hydrogen storage are described.

  5. Doping of metal-organic frameworks with functional guest molecules and nanoparticles.

    PubMed

    Schröder, Felicitas; Fischer, Roland A

    2010-01-01

    Nanoparticle synthesis within metal-organic frameworks (MOFs) is performed by the adsorption of suitable precursor molecules for the metal component and subsequent decomposition to the composite materials nanoparticles@ MOF. This chapter will review different approaches of loading MOFs with more complex organic molecules and metal-organic precursor molecules. The related reactions inside MOFs are discussed with a focus on stabilizing reactive intermediates in the corresponding cavities. The syntheses of metal and metal oxide nanoparticles inside MOFs are reviewed, and different synthetic routes compared. Emphasis is placed on the micro structural characterization of the materials nanoparticles@MOF with a particular focus on the location of embedded nanoparticles using TEM methods. Some first examples of applications of the doped MOFs in heterogeneous catalysis and hydrogen storage are described.

  6. Metal-organic organopolymeric hybrid framework by reversible [2+2] cycloaddition reaction.

    PubMed

    Park, In-Hyeok; Chanthapally, Anjana; Zhang, Zhenjie; Lee, Shim Sung; Zaworotko, Michael J; Vittal, Jagadese J

    2014-01-07

    Organic polymers are usually amorphous or possess very low crystallinity. The metal complexes of organic polymeric ligands are also difficult to crystallize by traditional methods because of their poor solubilities and their 3D structures can not be determined by single-crystal X-ray crystallography owing to a lack of single crystals. Herein, we report the crystal structure of a 1D Zn(II) coordination polymer fused with an organic polymer ligand made in situ by a [2+2] cycloaddition reaction of a six-fold interpenetrated metal-organic framework. It is also shown that this organic polymer ligand can be depolymerized in a single-crystal-to-single-crystal (SCSC) fashion by heating. This strategy could potentially be extended to make a range of monocrystalline metal organopolymeric complexes and metal-organic organopolymeric hybrid materials. Such monocrystalline metal complexes of organic polymers have hitherto been inaccessible for materials researchers.

  7. Metal organic frameworks for the catalytic detoxification of chemical warfare nerve agents

    DOEpatents

    Hupp, Joseph T.; Farha, Omar K.; Katz, Michael J.; Mondloch, Joseph E.

    2017-04-18

    A method of using a metal organic framework (MOF) comprising a metal ion and an at least bidendate organic ligand to catalytically detoxify chemical warfare nerve agents including exposing the metal-organic-framework (MOF) to the chemical warfare nerve agent and catalytically decomposing the nerve agent with the MOF.

  8. Metal-organic frameworks for adsorption and separation of noble gases

    DOEpatents

    Allendorf, Mark D.; Greathouse, Jeffery A.; Staiger, Chad

    2017-05-30

    A method including exposing a gas mixture comprising a noble gas to a metal organic framework (MOF), including an organic electron donor and an adsorbent bed operable to adsorb a noble gas from a mixture of gases, the adsorbent bed including a metal organic framework (MOF) including an organic electron donor.

  9. An ordered bcc CuPd nanoalloy synthesised via the thermal decomposition of Pd nanoparticles covered with a metal-organic framework under hydrogen gas.

    PubMed

    Li, Guangqin; Kobayashi, Hirokazu; Kusada, Kohei; Taylor, Jared M; Kubota, Yoshiki; Kato, Kenichi; Takata, Masaki; Yamamoto, Tomokazu; Matsumura, Syo; Kitagawa, Hiroshi

    2014-11-18

    Presented here is the synthesis of an ordered bcc copper-palladium nanoalloy, via the decomposition of a Pd nanoparticle@metal-organic framework composite material. In situ XRD measurements were performed in order to understand the mechanism of the decomposition process. This result gives a further perspective into the synthesis of new nanomaterials via metal-organic framework decomposition.

  10. Tuning hydrogen sorption properties of metal-organic frameworks by postsynthetic covalent modification.

    PubMed

    Wang, Zhenqiang; Tanabe, Kristine K; Cohen, Seth M

    2010-01-04

    Postsynthetic modification is presented as a means to tune the hydrogen adsorption properties of a series of metal-organic frameworks (MOFs). IRMOF-3 (isoreticular metal-organic framework), UMCM-1-NH(2) (University of Michigan crystalline material), and DMOF-1-NH(2) (DABCO metal-organic framework) have been covalently modified with a series of anhydrides or isocyanates and the hydrogen sorption properties have been studied. Both the storage capacities and isosteric heats of adsorption clearly show that covalent postsynthetic modification can significantly enhance the sorption affinity of MOFs with hydrogen and in some cases increase both gravimetric and volumetric uptake of the gas as much as 40 %. The significance of the present study is illustrated by: 1) the nature of the substituents introduced by postsynthetic modification result in different effects on the binding of hydrogen; 2) the covalent postsynthetic modification approach allows for systematic modulation of hydrogen sorption properties; and 3) the ease of postsynthetic modification of MOFs allows a direct evaluation of the interplay between MOF structure, hydrogen uptake, and heat of adsorption. The findings presented herein show that postsynthetic modification is a powerful method to manipulate and better understand the gas sorption properties of MOFs.

  11. Homochiral metal-organic framework used as a stationary phase for high-performance liquid chromatography.

    PubMed

    Kong, Jiao; Zhang, Mei; Duan, Ai-Hong; Zhang, Jun-Hui; Yang, Rui; Yuan, Li-Ming

    2015-02-01

    Metal-organic frameworks are promising porous materials. Chiral metal-organic frameworks have attracted considerable attention in controlling enantioselectivity. In this study, a homochiral metal-organic framework [Co(2) (D-cam)(2) (TMDPy)] (D-cam = D-camphorates, TMDPy = 4,4'-trimethylenedipyridine) with a non-interpenetrating primitive cubic net has been used as a chiral stationary phase in high-performance liquid chromatography. It has allowed the successful separation of six positional isomers and six chiral compounds. The good selectivity and baseline separation, or at least 60% valley separation, confirmed its excellent molecular recognition characteristics. The relative standard deviations for the retention time of run-to-run and column-to-column were less than 1.8 and 3.1%, respectively. These results demonstrate that [Co(2) (D-cam)(2) (TMDPy)] may represent a promising chiral stationary phase for use in high-performance liquid chromatography. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Capture of organic iodides from nuclear waste by metal-organic framework-based molecular traps.

    PubMed

    Li, Baiyan; Dong, Xinglong; Wang, Hao; Ma, Dingxuan; Tan, Kui; Jensen, Stephanie; Deibert, Benjamin J; Butler, Joseph; Cure, Jeremy; Shi, Zhan; Thonhauser, Timo; Chabal, Yves J; Han, Yu; Li, Jing

    2017-09-07

    Effective capture of radioactive organic iodides from nuclear waste remains a significant challenge due to the drawbacks of current adsorbents such as low uptake capacity, high cost, and non-recyclability. We report here a general approach to overcome this challenge by creating radioactive organic iodide molecular traps through functionalization of metal-organic framework materials with tertiary amine-binding sites. The molecular trap exhibits a high CH3I saturation uptake capacity of 71 wt% at 150 °C, which is more than 340% higher than the industrial adsorbent Ag(0)@MOR under identical conditions. These functionalized metal-organic frameworks also serve as good adsorbents at low temperatures. Furthermore, the resulting adsorbent can be recycled multiple times without loss of capacity, making recyclability a reality. In combination with its chemical and thermal stability, high capture efficiency and low cost, the adsorbent demonstrates promise for industrial radioactive organic iodides capture from nuclear waste. The capture mechanism was investigated by experimental and theoretical methods.Capturing radioactive organic iodides from nuclear waste is important for safe nuclear energy usage, but remains a significant challenge. Here, Li and co-workers fabricate a stable metal-organic framework functionalized with tertiary amine groups that exhibits high capacities for radioactive organic iodides uptake.

  13. Computational studies of adsorption in metal organic frameworks and interaction of nanoparticles in condensed phases

    SciTech Connect

    Annapureddy, Harsha V.; Motkuri, Radha K.; Nguyen, Phuong T.; Truong, T. B.; Thallapally, Praveen K.; McGrail, B. Peter; Dang, Liem X.

    2014-01-08

    In this review, we describe recent efforts in which computer simulations were used to systematically study nano-structured metal organic frameworks, with particular emphasis on their application in heating and cooling processes. These materials also are known as metal organic heat carriers. We used both molecular dynamics and Grand Canonical Monte Carlo simulation techniques to gain a molecular-level understanding of the adsorption mechanism of gases in these porous materials. We investigated the uptake of various gases such as refrigerants R12 and R143a and also the elemental gases Xe and Rn by the metal organic framework (i.e., Ni2(dhtp)). We also evaluated the effects of temperature and pressure on the uptake mechanism. Our computed results compared reasonably well with available experimental measurements, thus validating our potential models and approaches. In addition, we also investigated the structural, diffusive, and adsorption properties of different hydrocarbons in Ni2(dhtp). To elucidate the mechanism of nanoparticle dispersion in condensed phases, we also studied the interactions among nanoparticles in various liquids, such as n-hexane, water and methanol. This work was performed at Pacific Northwest National Laboratory (PNNL) and was supported by the Division of Chemical Sciences, Geosciences and Biosciences, Office of Basic Energy Sciences, U.S. Department of Energy (DOE). PNNL is operated by Battelle for the DOE. The authors also gratefully acknowledge support received from the National Energy Technology Laboratory of DOE's Office of Fossil Energy.

  14. Template-Directed Approach Towards the Realization of Ordered Heterogeneity in Bimetallic Metal-Organic Frameworks.

    PubMed

    Kim, Daeok; Coskun, Ali

    2017-03-29

    Controlling the arrangement of different metal ions to achieve ordered heterogeneity in metal-organic frameworks (MOFs) has been a great challenge. Herein, we introduce a template-directed approach, in which a 1D metal-organic polymer incorporating well-defined binding pockets for the secondary metal ions used as a structural template and starting material for the preparation of well-ordered bimetallic MOF-74s under heterogeneous-phase hydrothermal reaction conditions in the presence of secondary metal ions such as Ni(2+) and Mg(2+) in 3 h. The resulting bimetallic MOF-74s were found to possess a nearly 1:1 metal ratio regardless of their initial stoichiometry in the reaction mixture, thus demonstrating the possibility of controlling the arrangement of metal ions within the secondary building blocks in MOFs to tune their intrinsic properties such as gas affinity.

  15. Computational studies of adsorption in metal organic frameworks and interaction of nanoparticles in condensed phases

    SciTech Connect

    Annapureddy, HVR; Motkuri, RK; Nguyen, PTM; Truong, TB; Thallapally, PK; McGrail, BP; Dang, LX

    2014-02-05

    In this review, we describe recent efforts to systematically study nano-structured metal organic frameworks (MOFs), also known as metal organic heat carriers, with particular emphasis on their application in heating and cooling processes. We used both molecular dynamics and grand canonical Monte Carlo simulation techniques to gain a molecular-level understanding of the adsorption mechanism of gases in these porous materials. We investigated the uptake of various gases such as refrigerants R12 and R143a. We also evaluated the effects of temperature and pressure on the uptake mechanism. Our computed results compared reasonably well with available measurements from experiments, thus validating our potential models and approaches. In addition, we investigated the structural, diffusive and adsorption properties of different hydrocarbons in Ni-2(dhtp). Finally, to elucidate the mechanism of nanoparticle dispersion in condensed phases, we studied the interactions among nanoparticles in various liquids, such as n-hexane, water and methanol.

  16. The Importance of Polymorphism in Metal-Organic Framework Studies.

    PubMed

    Aulakh, Darpandeep; Varghese, Juby R; Wriedt, Mario

    2015-09-08

    Polymorphic phase transitions remain frequently undetected in routine metal-organic framework (MOF) studies; however, their discovery is of major importance in interpreting structure-property relationships. We herein report a reversible enantiotropic single-crystal to single-crystal polymorphic phase transition of a new microporous MOF [Eu(BDC)(NO3)(DMF)2]n (H2BDC = 1,4-benzenedicarboxylic acid; DMF = dimethylformamide). While modification 1LT at 170 K crystallizes in the monoclinic space group P21/c with unit cell dimensions of a = 17.673(2) Å, b = 20.023(2) Å, c = 10.555(9) Å, β = 90.129(4)°, modification 1HT at 290 K crystallizes in higher symmetry space group C2/c with unit cell dimensions of a = 17.200(7) Å, b = 10.737(4) Å, c = 10.684(4) Å, β = 90.136(2)°. This temperature-induced phase transition is accompanied by a small change in the solvent-accessible voids from 46.8 in 1LT to 49.8% in 1HT, which triggers a significant change in the adsorption properties as compared to a reported isostructural compound. Detailed investigations on the phase transition were studied with variable-temperature single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction, and differential scanning calorimetry measurements. The herein-presented investigations emphasize the importance of polymorphic phase transitions in routine MOF studies originating from low-temperature SCXRD data and high-temperature physical property characterizations in avoiding the use of a wrong structure in interpreting structure-property relationships.

  17. Metal-Organic Frameworks for Heterogeneous Basic Catalysis.

    PubMed

    Zhu, Li; Liu, Xiao-Qin; Jiang, Hai-Long; Sun, Lin-Bing

    2017-06-28

    Great attention has been given to metal-organic frameworks (MOFs)-derived solid bases because of their attractive structure and catalytic performance in various organic reactions. The extraordinary skeleton structure of MOFs provides many possibilities for incorporation of diverse basic functionalities, which is unachievable for conventional solid bases. The past decade has witnessed remarkable advances in this vibrant research area; however, MOFs for heterogeneous basic catalysis have never been reviewed until now. Therefore, a review summarizing MOFs-derived base catalysts is highly expected. In this review, we present an overview of the recent progress in MOFs-derived solid bases covering preparation, characterization, and catalytic applications. In the preparation section, the solid bases are divided into two categories, namely, MOFs with intrinsic basicity and MOFs with modified basicity. The basicity can originate from either metal sites or organic ligands. Different approaches used for generation of basic sites are included, and each approach is described with representative examples. The fundamental principles for the design and fabrication of MOFs with basic functionalities are featured. In the characterization section, experimental techniques and theoretical calculations employed for characterization of basic MOFs are summarized. Some representive experimental techniques, such as temperature-programmed desorption of CO2 (CO2-TPD) and infrared (IR) spectra of different probing molecules, are covered. Following preparation and characterization, the catalytic applications of MOFs-derived solid bases are dealt with. These solid bases have potential to catalyze some well-known "base-catalyzed reactions" like Knoevenagel condensation, aldol condensation, and Michael addition. Meanwhile, in contrast to conventional solid bases, MOFs show some different catalytic properties due to their special structural and surface properties. Remarkably, characteristic

  18. High-internal-phase emulsions stabilized by metal-organic frameworks and derivation of ultralight metal-organic aerogels

    PubMed Central

    Zhang, Bingxing; Zhang, Jianling; Liu, Chengcheng; Peng, Li; Sang, Xinxin; Han, Buxing; Ma, Xue; Luo, Tian; Tan, Xiuniang; Yang, Guanying

    2016-01-01

    To design high-internal-phase emulsion (HIPE) systems is of great interest from the viewpoints of both fundamental researches and practical applications. Here we demonstrate for the first time the utilization of metal-organic framework (MOF) for HIPE formation. By stirring the mixture of water, oil and MOF at room temperature, the HIPE stabilized by the assembly of MOF nanocrystals at oil-water interface could be formed. The MOF-stabilized HIPE provides a novel route to produce highly porous metal-organic aerogel (MOA) monolith. After removing the liquids from the MOF-stabilized HIPE, the ultralight MOA with density as low as 0.01 g·cm−3 was obtained. The HIPE approach for MOA formation has unique advantages and is versatile in producing different kinds of ultralight MOAs with tunable porosities and structures. PMID:26892258

  19. High-internal-phase emulsions stabilized by metal-organic frameworks and derivation of ultralight metal-organic aerogels

    NASA Astrophysics Data System (ADS)

    Zhang, Bingxing; Zhang, Jianling; Liu, Chengcheng; Peng, Li; Sang, Xinxin; Han, Buxing; Ma, Xue; Luo, Tian; Tan, Xiuniang; Yang, Guanying

    2016-02-01

    To design high-internal-phase emulsion (HIPE) systems is of great interest from the viewpoints of both fundamental researches and practical applications. Here we demonstrate for the first time the utilization of metal-organic framework (MOF) for HIPE formation. By stirring the mixture of water, oil and MOF at room temperature, the HIPE stabilized by the assembly of MOF nanocrystals at oil-water interface could be formed. The MOF-stabilized HIPE provides a novel route to produce highly porous metal-organic aerogel (MOA) monolith. After removing the liquids from the MOF-stabilized HIPE, the ultralight MOA with density as low as 0.01 g·cm-3 was obtained. The HIPE approach for MOA formation has unique advantages and is versatile in producing different kinds of ultralight MOAs with tunable porosities and structures.

  20. Electrodeposition of WO3 nanoparticles into surface mounted metal-organic framework HKUST-1 thin films

    NASA Astrophysics Data System (ADS)

    Yoo, Hyeonseok; Welle, Alexander; Guo, Wei; Choi, Jinsub; Redel, Engelbert

    2017-03-01

    We describe a novel procedure to fabricate WO3@surface-mounted metal-organic framework (SURMOF) hybrid materials by electrodeposition of WO3 nanoparticles into HKUST-1, also termed Cu3(BTC)2 SURMOFs. These materials have been characterized using x-ray diffraction, time-of-flight secondary ion mass spectrometry, scanning electron microscopy, x-ray photoelectron spectroscopy as well as linear sweep voltammetry. The WO3 semiconductor/SURMOF heterostructures were further tested as hybrid electrodes in their performance for hydrogen evolution reaction from water.

  1. Electrodeposition of WO3 nanoparticles into surface mounted metal-organic framework HKUST-1 thin films.

    PubMed

    Yoo, Hyeonseok; Welle, Alexander; Guo, Wei; Choi, Jinsub; Redel, Engelbert

    2017-03-17

    We describe a novel procedure to fabricate WO3@surface-mounted metal-organic framework (SURMOF) hybrid materials by electrodeposition of WO3 nanoparticles into HKUST-1, also termed Cu3(BTC)2 SURMOFs. These materials have been characterized using x-ray diffraction, time-of-flight secondary ion mass spectrometry, scanning electron microscopy, x-ray photoelectron spectroscopy as well as linear sweep voltammetry. The WO3 semiconductor/SURMOF heterostructures were further tested as hybrid electrodes in their performance for hydrogen evolution reaction from water.

  2. Continuous-Flow Microwave Synthesis of Metal-Organic Frameworks: A Highly Efficient Method for Large-Scale Production.

    PubMed

    Taddei, Marco; Steitz, Daniel Antti; van Bokhoven, Jeroen Anton; Ranocchiari, Marco

    2016-03-01

    Metal-organic frameworks are having a tremendous impact on novel strategic applications, with prospective employment in industrially relevant processes. The development of such processes is strictly dependent on the ability to generate materials with high yield efficiency and production rate. We report a versatile and highly efficient method for synthesis of metal-organic frameworks in large quantities using continuous flow processing under microwave irradiation. Benchmark materials such as UiO-66, MIL-53(Al), and HKUST-1 were obtained with remarkable mass, space-time yields, and often using stoichiometric amounts of reactants. In the case of UiO-66 and MIL-53(Al), we attained unprecedented space-time yields far greater than those reported previously. All of the syntheses were successfully extended to multi-gram high quality products in a matter of minutes, proving the effectiveness of continuous flow microwave technology for the large scale production of metal-organic frameworks.

  3. A new strategy for storage and transportation of sensitive high-energy materials: guest-dependent energy and sensitivity of 3D metal-organic-framework-based energetic compounds.

    PubMed

    Zhang, Sheng; Liu, Xiangyu; Yang, Qi; Su, Zhiyong; Gao, Wenjuan; Wei, Qing; Xie, Gang; Chen, Sanping; Gao, Shengli

    2014-06-23

    Reaction of Co(II) with the nitrogen-rich ligand N,N-bis(1H-tetrazole-5-yl)-amine (H2bta) leads to a mixed-valence, 3D, porous, metal-organic framework (MOF)-based, energetic material with the nitrogen content of 51.78%, [Co9(bta)10(Hbta)2(H2O)10]n⋅(22 H2O)n (1). Compound 1 was thermohydrated to produce a new, stable, energetic material with the nitrogen content of 59.85% and heat of denotation of 4.537 kcal cm(-3), [Co9(bta)10(Hbta)2(H2O)10]n (2). Sensitivity tests show that 2 is more sensitivity to external stimuli than 1, reflecting guest-dependent energy and sensitivity of 3D, MOF-based, energetic materials. Less-sensitive 1 can be regarded as a more safe form for storage and transformation to sensitive 2. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Preparation, Characterization, and Postsynthetic Modification of Metal-Organic Frameworks: Synthetic Experiments for an Undergraduate Laboratory Course in Inorganic Chemistry

    ERIC Educational Resources Information Center

    Sumida, Kenji; Arnold, John

    2011-01-01

    Metal-organic frameworks (MOFs) are crystalline materials that are composed of an infinite array of metal nodes (single ions or clusters) linked to one another by polyfunctional organic compounds. Because of their extraordinary surface areas and high degree of control over the physical and chemical properties, these materials have received much…

  5. Preparation, Characterization, and Postsynthetic Modification of Metal-Organic Frameworks: Synthetic Experiments for an Undergraduate Laboratory Course in Inorganic Chemistry

    ERIC Educational Resources Information Center

    Sumida, Kenji; Arnold, John

    2011-01-01

    Metal-organic frameworks (MOFs) are crystalline materials that are composed of an infinite array of metal nodes (single ions or clusters) linked to one another by polyfunctional organic compounds. Because of their extraordinary surface areas and high degree of control over the physical and chemical properties, these materials have received much…

  6. Water adsorption and proton conduction in metal-organic frameworks: Insights from molecular simulations

    NASA Astrophysics Data System (ADS)

    Paesani, Francesco

    2014-03-01

    Metal-organic frameworks (MOFs) are a relatively new class of porous materials that hold great potential for a wide range of applications in chemistry, materials science, and nanoengineering. Compared to other porous materials such as zeolites, MOF properties are highly tunable. In particular, it has been shown that both size and shape of the MOF pores can be rationally designed for specific applications. For example, the ability to modify the framework properties with respect to hydrophilicity/hydrophobicity and acidity/basicity can enable the direct control of proton conduction through carrier molecules adsorbed inside the pores. Here, I report on our current efforts aimed at providing a molecular-level characterization of water-mediated proton conduction through the MOF pores. Particular emphasis will be put on correlation between proton conduction and both structural and chemical properties of the frameworks as well as on the dynamical behavior of water confined in the MOF pores. NSF award number: DMR-130510

  7. Flexible and hydrophobic Zn-based metal-organic framework.

    PubMed

    Hauptvogel, Ines Maria; Biedermann, Ralf; Klein, Nicole; Senkovska, Irena; Cadiau, Amandine; Wallacher, Dirk; Feyerherm, Ralf; Kaskel, Stefan

    2011-09-05

    A zinc-based metal-organic framework Zn(2)(adb)(2)(dabco)·4.5 DMF (K) (DUT-30(Zn), DUT = Dresden University of Technology, adb = 9,10-anthracene dibenzoate, dabco =1,4-diazabicyclo[2.2.2]octane, DMF = N,N-dimethylformamide) was synthesized using a solvothermal route. This MOF exhibits six crystallographic guest dependent phases. Two of them were characterized via single crystal X-ray analysis. The as-synthesized phase K crystallizes in the orthorhombic space group Fmmm, with a = 9.6349(9), b = 26.235(3), and c = 28.821(4) Å and consists of two interpenetrated pillar-layer networks with pcu topology. When the substance loses 0.5 DMF molecules per formula unit, a phase transition from the kinetic phase K to a thermodynamic phase T occurs. Zn(2)(adb)(2)(dabco)·4 DMF (T) crystallizes in the tetragonal space group I4/mmm, with a = 19.5316(8) and c = 9.6779(3) Å. During the evacuation the DUT-30(Zn) undergoes again the structural transformation to A. The activated compound A shows the gate pressure effect in the low pressure region of nitrogen physisorption isotherm and has a BET surface area of 960 m(2 )g(-1) and a specific pore volume of 0.43 cm(3) g(-1). Furthermore, DUT-30(Zn) exhibits a hydrogen storage capacity of 1.12 wt % at 1 bar, a CO(2) uptake of 200 cm(3) g(-1) at -78 °C and 0.9 bar, and a n-butane uptake of 3.0 mmol·g(-1) at 20 °C. The N(2) adsorption process was monitored in situ via X-ray powder diffraction using synchrotron radiation. A low temperature induced transformation of phase A to phase V could be observed if the compound was cooled under vacuum to -196 °C. A further crystalline phase N could be identified if the framework was filled with nitrogen at -196 °C. Additionally, the treatment of activated phase A with water leads to the new phase W.

  8. Ionic liquid accelerates the crystallization of Zr-based metal-organic frameworks.

    PubMed

    Sang, Xinxin; Zhang, Jianling; Xiang, Junfeng; Cui, Jie; Zheng, Lirong; Zhang, Jing; Wu, Zhonghua; Li, Zhihong; Mo, Guang; Xu, Yuan; Song, Jinliang; Liu, Chengcheng; Tan, Xiuniang; Luo, Tian; Zhang, Bingxing; Han, Buxing

    2017-08-02

    The Zr-based metal-organic frameworks are generally prepared by solvothermal procedure. To overcome the slow kinetics of nucleation and crystallization of Zr-based metal-organic frameworks is of great interest and challenging. Here, we find that an ionic liquid as solvent can significantly accelerate the formation of Zr-based metal-organic frameworks at room temperature. For example, the reaction time is shortened to 0.5 h in 1-hexyl-3-methylimidazolium chloride for Zr-based metal-organic framework formation, while that in the conventional solvent N,N-dimethylformamide needs at least 120 h. The reaction mechanism was investigated in situ by (1)H nuclear magnetic resonance, spectroscopy synchrotron small angle X-ray scattering and X-ray absorption fine structure. This rapid, low-energy, and facile route produces Zr-based metal-organic framework nanoparticles with small particle size, missing-linker defects and large surface area, which can be used as heterogeneous catalysts for Meerwein-Ponndorf-Verley reaction.Crystallization kinetics of metal-organic frameworks in conventional organic solvents are usually very slow. Here, the authors show that an ionic liquid medium accelerates considerably the formation of Zr-based metal-organic frameworks that are active catalysts in the Meerwein-Ponndorf-Verley reaction.

  9. Metal-organic frameworks based on uranyl and phosphonate ligands.

    PubMed

    Monteiro, Bernardo; Fernandes, José A; Pereira, Cláudia C L; Vilela, Sérgio M F; Tomé, João P C; Marçalo, Joaquim; Almeida Paz, Filipe A

    2014-02-01

    Three new crystalline metal-organic frameworks have been prepared from the reaction of uranyl nitrate with nitrilotris(methylphosphonic acid) [H6nmp, N(CH2PO3H2)3], 1,4-phenylenebis(methylene)diphosphonic acid [H4pmd, C6H4(PO3H2)2], and (benzene-1,3,5-triyltris(methylene))triphosphonic acid [H6bmt, C6H3(PO3H2)3]. Compound [(UO2)2F(H3nmp)(H2O)]·4H2O (I) crystallizes in space group C2/c, showing two crystallographically independent uranyl centres with pentagonal bipyramidal coordination geometries. While one metal centre is composed of a {(UO2)O3(μ-F)}2 dimer, the other comprises an isolated {(UO2)O5} polyhedron. Compound [(UO2)(H2pmd)] (II) crystallizes in space group P21/c, showing a centrosymmetric uranyl centre with an octahedral {(UO2)O4} coordination geometry. Compound [(UO2)3(H3bmt)2(H2O)2]·14H2O (III) crystallizes in space group P\\bar 1, showing two crystallographically independent uranyl centres. One uranyl centre is a {(UO2)O5} pentagonal bipyramid similar to that in (I), while the other is a {(UO2)O4} centrosymmetric octahedron similar to that in (II). Compounds (I) and (III) contain solvent-accessible volumes accounting for ca 23.6 and 26.9% of their unit-cell volume, respectively. In (I) the cavity has a columnar shape and is occupied by disordered water molecules, while in (III) the cavity is a two-dimensional layer with more ordered water molecules. All compounds have been studied in the solid state using FT-IR spectroscopy. Topological studies show that compounds (I) and (III) are trinodal, with 3,6,6- and 4,4,6-connected networks, respectively. Compound (II) is instead a 4-connected uninodal network of the type cds.

  10. Reaction Engineering with Metal-Organic Framework Catalysts

    NASA Astrophysics Data System (ADS)

    Melkonian, Arek Viken

    To date, there has been no comprehensive attempt to perform and/or describe catalytic reactions in the gas phase that utilize metal-organic frameworks (MOFs) as catalysts. In addition, there has been no attempt to reaction engineer these MOF catalysts in order to determine their regimes of optimal catalytic activity and possible limitations to their use. A zinc-based MOF that has been post-synthetically modified with a homogeneous palladium catalyst, Pd(CH 3CN)2Cl2, is used to catalyze the hydrogenation of propylene. The catalyst is assembled in a packed-bed reactor under a continuous flow of reactants. The reaction is optimized with respect to isoreticular metalation, reactant flow rate, and reactor temperature. Maximum catalytic conversion is found at intermediate metalations of 40% and 60%, high hydrogen flow of 50 ccm, and intermediate reactor temperatures of 100 °C and 150 °C. The MOF-60 catalyst is exposed to a traditional catalyst poison, carbon monoxide (CO). It is found that the MOF is reversibly poisoned upon introduction of CO. Upon poisoning, catalytic conversions rates of 90%-100% are dramatically reduced to less than 10%-30%, depending on the CO flow rate and the reactor temperature. The CO poisoning is shown to be reversible, a similar effect as found with palladium on carbon (Pd/C). The time scale of poisoning and recovery is very fast for both the MOF catalyst and Pd/C (approximately 10-30 seconds). Other effects of temperature on the MOF-40 are also investigated. At fixed reactant flow, the temperature grid is partitioned into finer steps of 10 °C to determine the temperature that yields the highest catalytic conversion. It is found that conversion is nearly uniform in the range between the highest conversions, i.e., conversion plateaus between the optimum temperatures. The catalyst also exhibits a weak thermal hysteresis. There is no significant improvement in conversion with thermal cycling after alternating the reactor temperature between

  11. Heterogeneity of functional groups in a metal-organic framework displays magic number ratios.

    PubMed

    Sue, Andrew C-H; Mannige, Ranjan V; Deng, Hexiang; Cao, Dennis; Wang, Cheng; Gándara, Felipe; Stoddart, J Fraser; Whitelam, Stephen; Yaghi, Omar M

    2015-05-05

    Multiple organic functionalities can now be apportioned into nanoscale domains within a metal-coordinated framework, posing the following question: how do we control the resulting combination of "heterogeneity and order"? Here, we report the creation of a metal-organic framework, MOF-2000, whose two component types are incorporated in a 2:1 ratio, even when the ratio of component types in the starting solution is varied by an order of magnitude. Statistical mechanical modeling suggests that this robust 2:1 ratio has a nonequilibrium origin, resulting from kinetic trapping of component types during framework growth. Our simulations show how other "magic number" ratios of components can be obtained by modulating the topology of a framework and the noncovalent interactions between component types, a finding that may aid the rational design of functional multicomponent materials.

  12. Direct observation of hydrogen adsorption sites and nanocage formation in metal-organic frameworks.

    PubMed

    Yildirim, T; Hartman, M R

    2005-11-18

    The hydrogen adsorption sites in MOF5 were determined using neutron powder diffraction along with first-principles calculations. The metal-oxide cluster is primarily responsible for the adsorption while the organic linker plays only a secondary role. Equally important, at low temperatures and high-concentration, molecules form unique interlinked high-symmetry nanoclusters with intermolecular distances as small as 3.0 Angstrom and H(2) uptake as high as 11 wt %. These results hold the key to optimizing metal-organic framework (MOF) materials for hydrogen storage applications and also suggest that MOFs can be used as templates to create artificial interlinked hydrogen nanocages with novel properties.

  13. Direct Observation of Hydrogen Adsorption Sites and Nanocage Formation in Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Yildirim, T.; Hartman, M. R.

    2005-11-01

    The hydrogen adsorption sites in MOF5 were determined using neutron powder diffraction along with first-principles calculations. The metal-oxide cluster is primarily responsible for the adsorption while the organic linker plays only a secondary role. Equally important, at low temperatures and high-concentration, H2 molecules form unique interlinked high-symmetry nanoclusters with intermolecular distances as small as 3.0 Å and H2 uptake as high as 11 wt %. These results hold the key to optimizing metal-organic framework (MOF) materials for hydrogen storage applications and also suggest that MOFs can be used as templates to create artificial interlinked hydrogen nanocages with novel properties.

  14. Photochromic metal-organic frameworks: reversible control of singlet oxygen generation.

    PubMed

    Park, Jihye; Feng, Dawei; Yuan, Shuai; Zhou, Hong-Cai

    2015-01-07

    The controlled generation of singlet oxygen is of great interest owing to its potential applications including industrial wastewater treatment, photochemistry, and photodynamic therapy. Two photochromic metal-organic frameworks, PC-PCN and SO-PCN, have been developed. A photochromic reaction has been successfully realized in PC-PCN while maintaining its single crystallinity. In particular, as a solid-state material which inherently integrates the photochromic switch and photosensitizer, SO-PCN has demonstrated reversible control of (1)O2 generation. Additionally, SO-PCN shows catalytic activity towards photooxidation of 1,5-dihydroxynaphthalene.

  15. Unprecedented selectivity in molecular recognition of carbohydrates by a metal-organic framework.

    PubMed

    Yabushita, Mizuho; Li, Peng; Bernales, Varinia; Kobayashi, Hirokazu; Fukuoka, Atsushi; Gagliardi, Laura; Farha, Omar K; Katz, Alexander

    2016-06-04

    Metal-organic framework (MOF) material NU-1000 adsorbs dimers cellobiose and lactose from aqueous solution, in amounts exceeding 1250 mg gNU-1000(-1) while completely excluding the adsorption of the monomer glucose, even in a competitive mode with cellobiose. The MOF also discriminates between dimers consisting of α and β linkages, showing no adsorption of maltose. Electronic structure calculations demonstrate that key to this selective molecular recognition is the number of favorable CH-π interactions made by the sugar with pyrene units of the MOF.

  16. [Synthesis and applications of chiral metal-organic framework in the selective separation of enantiomers].

    PubMed

    Qi, Xiaoyue; Li, Xianjiang; Bai, Yu; Liu, Huwei

    2016-01-01

    Chirality is a universal phenomenon in nature. Chiral separation is vitally important in drug development, agricultural chemistry, pharmacology, environmental science, biology and many other fields. Chiral metal-organic frameworks (MOFs) are a new group of porous materials with special topology and designable pore structures, as well as their high specific surface area, porosity, excellent thermal stability, solvent resistance, etc. Thus, chiral MOFs are promising with various applications in the field of analytical chemistry. This review summarizes the synthesis strategies of chiral MOFs and their applications in the selective separation of enantiomers, as well as related mechanism.

  17. Hierarchical Pore Development by Plasma Etching of Zr-Based Metal-Organic Frameworks.

    PubMed

    DeCoste, Jared B; Rossin, Joseph A; Peterson, Gregory W

    2015-12-07

    The typically stable Zr-based metal-organic frameworks (MOFs) UiO-66 and UiO-66-NH2 were treated with tetrafluoromethane (CF4 ) and hexafluoroethane (C2 F6 ) plasmas. Through interactions between fluoride radicals from the perfluoroalkane plasma and the zirconium-oxygen bonds of the MOF, the resulting materials showed the development of mesoporosity, creating a hierarchical pore structure. It is anticipated that this strategy can be used as a post-synthetic technique for developing hierarchical networks in a variety of MOFs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Review of Molecular Simulations of Methane Storage in Metal-Organic Frameworks.

    PubMed

    Lee, Seung-Joon; Bae, Youn-Sang

    2016-05-01

    Methane storage in porous materials is one of the hot issues because it can replace dangerous high-pressure compressed natural gas (CNG) tanks in natural gas vehicles. Among the diverse adsorbents, metal-organic frameworks (MOFs) are considered to be promising due to their extremely high surface areas and low crystal densities. Molecular simulation has been considered as an important tool for finding an appropriate MOF for methane storage. We review several important roles of molecular modeling for the studies of methane adsorption in MOFs.

  19. Second sphere coordination of hybrid metal-organic materials: solid state reactivity.

    PubMed

    Guo, Fang; Martí-Rujas, Javier

    2016-09-21

    When compared to other hybrid metal organic materials such as metal-organic frameworks, hydrogen bonded materials self-assembled by metals and organic molecules using second sphere interactions have been poorly investigated. Consequently, their solid-sate properties are also scarce. In this perspective, earlier research mainly on host-guest chemistry and its evolution towards more extended structures by applying crystal engineering principles using second sphere coordination is described. Crystal-to-crystal guest exchange reactions, permanently porous hybrid metal organic materials, mechanochemical reactivity, thermally induced phase transformations as well as some examples of functional technological applications using second sphere adducts such as gas adsorption, separation and non-linear optical phenomena are also reported. Although some tutorial reviews on second sphere adducts have been conducted mainly in the solution state focusing on metal based anion receptors, to the best of our knowledge, an overview on relevant works that focus on the solid-state properties has not been carried out. The aim of this article is to highlight from some of the early fundamental work to the latest reports on hybrid metal-organic materials self-assembled via second sphere interactions with a focus on solid-state chemistry.

  20. Assembly of a metal-organic framework by sextuple intercatenation of discrete adamantane-like cages.

    PubMed

    Kuang, Xiaofei; Wu, Xiaoyuan; Yu, Rongmin; Donahue, James P; Huang, Jinshun; Lu, Can-Zhong

    2010-06-01

    Metal-organic frameworks form a unique class of multifunctional hybrid materials and have myriad applications, including gas storage and catalysis. Their structure is usually achieved through the infinite coordination of metal ions and multidentate organic ligands by means of strong covalent bonds. Threaded molecules such as catenanes and rotaxanes have largely been restricted to comprising components of two-dimensional interlocking rings or polygons. There are very few examples of the catenation of polyhedral cages. Although it has been postulated that the infinite extended architecture can be obtained from the polycatenation of a discrete cage based on such threading, this has not been documented to date. Here we describe an infinite three-dimensional metal-organic framework composed of catenated polyhedral cages, in which the framework is achieved by mechanical interlocking of all of the vertices of the cages. The three-dimensional polycatenated framework shows twofold self-interpenetration in its crystal packing. The penetration of polycatenanes creates nanosized voids into which the Keggin polyoxometalate anions are perfectly accommodated as counteranions.

  1. Facile electrosynthesis of nano flower like metal-organic framework and its nanocomposite with conjugated polymer as a novel and hybrid electrode material for highly capacitive pseudocapacitors.

    PubMed

    Naseri, Maryam; Fotouhi, Lida; Ehsani, Ali; Dehghanpour, Saeed

    2016-12-15

    The [Cu(btec)0.5DMF] (H4btec=1,2,4,5-benzenetetracarboxylate acid) was electrosynthesized on the graphite working electrode by applying catholic potential. The [Cu(btec)0.5DMF] grows on a graphite surface which results from the coordination of 1,2,4,5-benzenetetracarboxylate anions with Cu(2+) cations. The electrosynthesized [Cu(btec)0.5DMF] was characterized by X-ray diffraction, scanning electron microscopy. Furthermore, POAP/Cu(btec)0.5DMF nanocomposite film electrosynthesized on the surface of the carbon paste electrode by cyclic voltammetry. Different electrochemical methods including galvanostatic charge-discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy are carried out in order to investigate the performance of the system. This work introduces new nanocomposite materials for electrochemical redox capacitors with advantages including ease synthesis, high active surface area and stability in an aqueous electrolyte.

  2. Ferroelectric metal-organic framework with a high dielectric constant.

    PubMed

    Ye, Qiong; Song, Yu-Mei; Wang, Guo-Xi; Chen, Kai; Fu, Da-Wei; Chan, Philip Wai Hong; Zhu, Jin-Song; Huang, Songping D; Xiong, Ren-Gen

    2006-05-24

    Hydrothermal reaction of (l)-N-(4'-cyanobenzy)-(S)-proline with CdCl2 as a Lewis acid catalyst and NaN3 gives colorless block compound 1, in which 1 displays a complicated 3D framework. Ferroelectric and dielectric property measurements reveal that 1 exhibits physical properties comparable to that of a typical ferroelectric compound with a dipole relaxation process and a dielectric constant of ca. 38.6 that makes it, by definition, a high dielectric material.

  3. Evaluating metal-organic frameworks for post-combustion carbon dioxide capture via temperature swing adsorption

    SciTech Connect

    Mason, JA; Sumida, K; Herm, ZR; Krishna, R; Long, JR

    2011-08-01

    Two representative metal-organic frameworks, Zn4O(BTB)(2)(BTB3- = 1,3,5-benzenetribenzoate; MOF-177) and Mg-2(dobdc) (dobdc(4-) = 1,4-dioxido-2,5-benzenedicarboxylate; Mg-MOF-74, CPO-27-Mg), are evaluated in detail for their potential use in post-combustion CO2 capture via temperature swing adsorption (TSA). Low-pressure single-component CO2 and N-2 adsorption isotherms were measured every 10 degrees C from 20 to 200 degrees C, allowing the performance of each material to be analyzed precisely. In order to gain a more complete understanding of the separation phenomena and the thermodynamics of CO2 adsorption, the isotherms were analyzed using a variety of methods. With regard to the isosteric heat of CO2 adsorption, Mg-2(dobdc) exhibits an abrupt drop at loadings approaching the saturation of the Mg2+ sites, which has significant implications for regeneration in different industrial applications. The CO2/N-2 selectivities were calculated using ideal adsorbed solution theory (IAST) for MOF-177, Mg-2(dobdc), and zeolite NaX, and working capacities were estimated using a simplified TSA model. Significantly, MOF-177 fails to exhibit a positive working capacity even at regeneration temperatures as high as 200 degrees C, while Mg-2(dobdc) reaches a working capacity of 17.6 wt% at this temperature. Breakthrough simulations were also performed for the three materials, demonstrating the superior performance of Mg-2(dobdc) over MOF-177 and zeolite NaX. These results show that the presence of strong CO2 adsorption sites is essential for a metal-organic framework to be of utility in post-combustion CO2 capture via a TSA process, and present a methodology for the evaluation of new metal-organic frameworks via analysis of single-component gas adsorption isotherms.

  4. Rapid syntheses of a metal-organic framework material Cu3(BTC)2(H2O)3 under microwave: a quantitative analysis of accelerated syntheses.

    PubMed

    Khan, Nazmul Abedin; Haque, Enamul; Jhung, Sung Hwa

    2010-03-20

    A typical MOF material, Cu-BTC has been synthesized with microwave and conventional electric heating in various conditions to elucidate, for the first time, the quantitative acceleration in the synthesis of a MOF by microwaves. The acceleration by microwaves is mainly due to rapid nucleation rather than rapid crystal growth, even though both stages are accelerated. The acceleration in the nucleation stage by microwaves is due to the very large pre-exponential factor (about 1.4 x 10(10) times that of conventional synthesis) in the Arrhenius plot. However, the activation energy for the nucleation in the case of microwave synthesis is higher than the activation energy of conventional synthesis. The large acceleration in the nucleation, compared with that in the crystal growth, is observed once again by the syntheses in two-steps (changing heating methods from microwave into conventional heating or from conventional heating into microwave heating just after the nucleation is completed). The crystal size of Cu-BTC obtained by microwave-nucleation is generally smaller than the Cu-BTC made by conventional-nucleation, probably due to rapid nucleation and the small size of nuclei with microwave-nucleation.

  5. A Highly Energetic N-Rich Zeolite-Like Metal-Organic Framework with Excellent Air Stability and Insensitivity.

    PubMed

    Qin, Jun-Sheng; Zhang, Ji-Chuan; Zhang, Min; Du, Dong-Ying; Li, Jing; Su, Zhong-Min; Wang, Yuan-Yuan; Pang, Si-Ping; Li, Sheng-Hua; Lan, Ya-Qian

    2015-12-01

    A stable N-rich aromatic ligand is employed to prepare energetic zeolite-like metal-organic frameworks. IFMC-1 shows excellent air stability, and the lowest sensitivity toward impact, friction, and electrostatic discharge and the highest predicted heat of detonation among the reported coordination polymers, and even commercial materials (such as trinitrotoluene (TNT)).

  6. A facilely synthesized amino-functionalized metal-organic framework for highly specific and efficient enrichment of glycopeptides.

    PubMed

    Zhang, Yi-Wei; Li, Ze; Zhao, Qiang; Zhou, Ying-Lin; Liu, Hu-Wei; Zhang, Xin-Xiang

    2014-10-09

    A facilely synthesized amino-functionalized metal-organic framework (MOF) MIL-101(Cr)-NH2 was first applied for highly specific glycopeptide enrichment based on the hydrophilic interactions. With the special characteristics of the MOF, the material performed well in selectivity and sensitivity for both standard glycoprotein samples and complex biological samples.

  7. Size-selective biocatalysis of myoglobin immobilized into a mesoporous metal-organic framework with hierarchical pore sizes.

    PubMed

    Chen, Yao; Lykourinou, Vasiliki; Hoang, Tran; Ming, Li-June; Ma, Shengqian

    2012-09-03

    The protein myoglobin has been successfully immobilized into a mesoporous metal-organic framework with hierarchical pore sizes, which demonstrates interesting size-selective biocatalysis as well as superior catalytic activities toward small substrate oxidation compared to its mesoporous silica material counterpart.

  8. Organizing mechanically interlocked molecules to function inside metal-organic frameworks.

    PubMed

    Zhu, Kelong; Loeb, Stephen J

    2014-01-01

    The idea that the workings of molecular switches, motors, and machines based on mechanically interlocked molecules can be transferred into the solid state by using them as the building blocks of metal-organic framework materials is addressed. This involves an in-depth review and analysis of the chemistry of coordination polymers and metal-organic frameworks in which the linkers are rotaxanes and catenanes. To date, two types of materials have been prepared: (1) coordination polymers in which the interlocked components are part of a complex architecture but do not display large amplitude molecular motion or function and (2) those that clearly demonstrate some type of supramolecular quality (molecular recognition) or relative motion between interlocked components (dynamics) reminiscent of their solution counterparts. The latter can be thought of as prototypes of solid-state molecular machines. The possibility of creating more sophisticated, solid-state materials that have the full characteristics of molecular switches, motors, and machines and the way forward for this chemistry is also discussed.

  9. A highly stable dynamic fluorescent metal-organic framework for selective sensing of nitroaromatic explosives.

    PubMed

    Gong, Yun-Nan; Jiang, Long; Lu, Tong-Bu

    2013-12-07

    A dynamic fluorescent metal-organic framework has been constructed using triphenylene-2,6,10-tricarboxylate and Tb(3+) as building blocks, which exhibits guest-responsive structural dynamism and selective sensing of nitroaromatic explosives.

  10. Magnetic Metal-Organic Frameworks for Efficient Carbon Dioxide Capture and Remote Trigger Release.

    PubMed

    Li, Haiqing; Sadiq, Muhammad Munir; Suzuki, Kiyonori; Ricco, Raffaele; Doblin, Christian; Hill, Anita J; Lim, Seng; Falcaro, Paolo; Hill, Matthew R

    2016-03-02

    Magnetic metal-organic framework (MOF) composites show highly efficient CO2 desorption capacities upon their exposure to an alternating magnetic field, demonstrating a magnetic induction swing strategy for potentially low-energy regeneration of MOF adsorbents.

  11. An amine-functionalized metal-organic framework as a sensing platform for DNA detection.

    PubMed

    Zhang, Hao-Tian; Zhang, Jian-Wei; Huang, Gang; Du, Zi-Yi; Jiang, Hai-Long

    2014-10-18

    An amine-functionalized metal-organic framework (MOF) has been employed as an effective fluorescent sensing platform for DNA detection and is capable of distinguishing complementary and mismatched target sequences with high sensitivity and selectivity.

  12. Kinetically tuned dimensional augmentation as a versatile synthetic route towards robust metal-organic frameworks.

    PubMed

    Feng, Dawei; Wang, Kecheng; Wei, Zhangwen; Chen, Ying-Pin; Simon, Cory M; Arvapally, Ravi K; Martin, Richard L; Bosch, Mathieu; Liu, Tian-Fu; Fordham, Stephen; Yuan, Daqiang; Omary, Mohammad A; Haranczyk, Maciej; Smit, Berend; Zhou, Hong-Cai

    2014-12-04

    Metal-organic frameworks with high stability have been pursued for many years due to the sustainability requirement for practical applications. However, researchers have had great difficulty synthesizing chemically ultra-stable, highly porous metal-organic frameworks in the form of crystalline solids, especially as single crystals. Here we present a kinetically tuned dimensional augmentation synthetic route for the preparation of highly crystalline and extremely robust metal-organic frameworks with a preserved metal cluster core. Through this versatile synthetic route, we obtain large single crystals of 34 different iron-containing metal-organic frameworks. Among them, PCN-250(Fe2Co) exhibits high volumetric uptake of hydrogen and methane, and is also stable in water and aqueous solutions with a wide range of pH values.

  13. Role of hydrocarbons in pore expansion and contraction of a flexible metal-organic framework

    SciTech Connect

    Motkuri, Radha K.; Thallapally, Praveen K.; Nune, Satish K.; Fernandez, Carlos A.; McGrail, B. Peter; Atwood, Jerry L.

    2011-05-06

    A flexible metal organic framework obtained from a flexible organic linker shows a breathing phenomenon upon adsorption of polar protic and non-polar solvents. Sorption profiles indicate favorable interactions with non-polar solvents over polar solvents.

  14. Textile/metal-organic-framework composites as self-detoxifying filters for chemical-warfare agents.

    PubMed

    López-Maya, Elena; Montoro, Carmen; Rodríguez-Albelo, L Marleny; Aznar Cervantes, Salvador D; Lozano-Pérez, A Abel; Cenís, José Luis; Barea, Elisa; Navarro, Jorge A R

    2015-06-01

    The current technology of air-filtration materials for protection against highly toxic chemicals, that is, chemical-warfare agents, is mainly based on the broad and effective adsorptive properties of hydrophobic activated carbons. However, adsorption does not prevent these materials from behaving as secondary emitters once they are contaminated. Thus, the development of efficient self-cleaning filters is of high interest. Herein, we report how we can take advantage of the improved phosphotriesterase catalytic activity of lithium alkoxide doped zirconium(IV) metal-organic framework (MOF) materials to develop advanced self-detoxifying adsorbents of chemical-warfare agents containing hydrolysable P-F, P-O, and C-Cl bonds. Moreover, we also show that it is possible to integrate these materials onto textiles, thereby combining air-permeation properties of the textiles with the self-detoxifying properties of the MOF material. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Engineering chiral porous metal-organic frameworks for enantioselective adsorption and separation

    NASA Astrophysics Data System (ADS)

    Peng, Yongwu; Gong, Tengfei; Zhang, Kang; Lin, Xiaochao; Liu, Yan; Jiang, Jianwen; Cui, Yong

    2014-07-01

    The separation of racemic molecules is of substantial significance not only for basic science but also for technical applications, such as fine chemicals and drug development. Here we report two isostructural chiral metal-organic frameworks decorated with chiral dihydroxy or -methoxy auxiliares from enantiopure tetracarboxylate-bridging ligands of 1,1‧-biphenol and a manganese carboxylate chain. The framework bearing dihydroxy groups functions as a solid-state host capable of adsorbing and separating mixtures of a range of chiral aromatic and aliphatic amines, with high enantioselectivity. The host material can be readily recycled and reused without any apparent loss of performance. The utility of the present adsorption separation is demonstrated in the large-scale resolution of racemic 1-phenylethylamine. Control experiments and molecular simulations suggest that the chiral recognition and separation are attributed to the different orientations and specific binding energies of the enantiomers in the microenvironment of the framework.

  16. Homochiral helical metal-organic frameworks of group 1 metals.

    PubMed

    Reger, Daniel L; Leitner, Andrew; Smith, Mark D; Tran, T Thao; Halasyamani, P Shiv

    2013-09-03

    The reactions of (S)-2-(1,8-naphthalimido)propanoic acid (HL(ala)) and (S)-2-(1,8-naphthalimido)-3-hydroxypropanoic acid (HL(ser)), protonated forms of ligands that contain a carboxylate donor group, an enantiopure chiral center, and a 1,8-naphthalimide π···π stacking supramolecular tecton and in the case of HL(ser) an alcohol functional group, with the appropriate alkali metal hydroxide followed by a variety of crystallization methods leads to the formation of crystalline K(L(ala))(MeOH) (1), K(L(ala))(H2O) (2), Na(L(ala))(H2O) (3), KL(ser) (4), CsL(ser) (5), and CsL(ala) (6). Each of these new complexes has a solid state structure based on six-coordinate metals linked into homochiral helical rod secondary building unit (SBU) central cores. In addition to the bonding of the carboxylate and solvent (in the case of L(ser) the ligand alcohol) to the metals, both oxygens on the 1,8-naphthalimide act as donor groups. One naphthalimide oxygen bonds to the same helical rod SBU as the carboxylate group of that ligand forming a chelate ring. The other naphthalimide oxygen bonds to adjacent SBUs. In complexes 1-3, this inter-rod link has a square arrangement bonding four other rods forming a three-dimensional enantiopure metal-organic framework (MOF) structure, whereas in 4-6 this link has a linear arrangement bonding two other rods forming a two-dimensional, sheet structure. In the latter case, the third dimension is supported exclusively by interdigitated π···π stacking interactions of the naphthalimide supramolecular tecton, forming enantiopure supramolecular MOF solids. Compounds 1-3 lose the coordinated solvent when heating above 100 °C. For 1, the polycrystalline powder reverts to 1 only by recrystallization from methanol, whereas compounds 2 and 3 undergo gas/solid, single-crystal to single-crystal transformations to form dehydrated compounds 2* and 3*, and rehydration occurs when crystals of these new complexes are left out in air. The reversible single

  17. Metal organic frameworks for enzyme immobilization in biofuel cells

    NASA Astrophysics Data System (ADS)

    Bodell, JaDee

    Interest in biofuel cells has been rapidly expanding as an ever-growing segment of the population gains access to electronic devices. The largest areas of growth for new populations using electronic devices are often in communities without electrical infrastructure. This lack of infrastructure in remote environments is one of the key driving factors behind the development of biofuel cells. Biofuel cells employ biological catalysts such as enzymes to catalyze oxidation and reduction reactions of select fuels to generate power. There are several benefits to using enzymes to catalyze reactions as compared to traditional fuel cells which use metal catalysts. First, enzymes are able to catalyze reactions at or near room temperature, whereas traditional metal catalysts are only efficient at very high temperatures. Second, biofuel cells can operate under mild pH conditions which is important for the eventual design of safe, commercially viable devices. Also, biofuel cells allow for implantable and flexible technologies. Finally, enzymes exhibit high selectivity and can be combined to fully oxidize or reduce the fuel which can generate several electrons from a single molecule of fuel, increasing the overall device efficiency. One of the main challenges which persist in biofuel cells is the instability of enzymes over time which tend to denature after hours or days. For a viable commercial biofuel cell to be produced, the stability of enzymes must be extended to months or years. Enzymes have been shown to have improved stability after being immobilized. The focus of this research was to find a metal organic framework (MOF) structure which could successfully immobilize enzymes while still allowing for electron transport to occur between the catalytic center of the enzyme and the electrode surface within a biofuel cell for power generation. Four MOF structures were successfully synthesized and were subsequently tested to determine the MOF's ability to immobilize the following

  18. Stimuli-Responsive DNA-Functionalized Metal-Organic Frameworks (MOFs).

    PubMed

    Kahn, Jason S; Freage, Lina; Enkin, Natalie; Garcia, Miguel Angel Aleman; Willner, Itamar

    2017-02-01

    The synthesis of nucleic acid-functionalized metal-organic frameworks (MOFs) is described. The metal-organic frameworks are loaded with a dye being locked in the structures by means of stimuli-responsive nucleic acid caps. The pH and K(+) -ion-triggered release, and switchable release, are demonstrated. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Metal-organic frameworks post-synthetically modified with ferrocenyl groups: framework effects on redox processes and surface conduction.

    PubMed

    Halls, Jonathan E; Hernán-Gómez, Alberto; Burrows, Andrew D; Marken, Frank

    2012-02-07

    Metal-organic framework (MOF) materials based on zinc(II) and aluminium(III) dicarboxylate frameworks with covalently attached ferrocene functional redox groups were synthesised by post-synthetic modification and investigated by voltammetry in aqueous and non-aqueous media. In the voltammetry experiments, ferrocene oxidation occurs in all cases, but chemically reversible and stable ferrocene oxidation without decay of the voltammetric response requires a "mild" dichloroethane solvent environment. The voltammetric response in this case is identified as "surface-confined" with fast surface-hopping of electrons and without affecting the bulk of MOF microcrystals. In aqueous media a more complex pH-dependent multi-stage redox process is observed associated with chemically irreversible bulk oxidation and disintegration of the MOF framework. A characteristic 30 mV per pH unit dependence of redox potentials is observed attributed to a "framework effect": the hydroxide-driven MOF framework dissolution.

  20. A novel metal-organic framework for high storage and separation of acetylene at room temperature

    SciTech Connect

    Duan, Xing; Wang, Huizhen; Ji, Zhenguo; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2016-09-15

    A novel 3D microporous metal-organic framework with NbO topology, [Cu{sub 2}(L)(H{sub 2}O){sub 2}]∙(DMF){sub 6}·(H{sub 2}O){sub 2} (ZJU-10, ZJU = Zhejiang University; H{sub 4}L =2′-hydroxy-[1,1′:4′,1″-terphenyl]-3,3″,5,5″-tetracarboxylic acid; DMF =N,N-dimethylformamide), has been synthesized and structurally characterized. With suitable pore sizes and open Cu{sup 2+} sites, ZJU-10a exhibits high BET surface area of 2392 m{sup 2}/g, as well as moderately high C{sub 2}H{sub 2} volumetric uptake capacity of 132 cm{sup 3}/cm{sup 3}. Meanwhile, ZJU-10a is a promising porous material for separation of acetylene from methane and carbon dioxide gas mixtures at room temperature. - Graphical abstract: A new NbO-type microporous metal-organic framework ZJU-10 with suitable pore size and open Cu{sup 2+} sites was synthesized to realize the strong interaction with acetylene molecules, which can separate the acetylene from methane and carbon dioxane gas mixtures at room temperature. Display Omitted - Highlights: • A novel 3D NbO-type microporous metal-organic framework ZJU-10 was solvothermally synthesized and structurally characterized. • ZJU-10a exhibits high BET surface area of 2392 m{sup 2}/g. • ZJU-10a shows a moderately high C{sub 2}H{sub 2} gravimetric (volumetric) uptake capacity of 174 (132) cm{sup 3}/g at 298 K and 1 bar. • ZJU-10a can separate acetylene from methane and carbon dioxide gas mixtures at room temperature.

  1. Enhanced ethylene separation and plasticization resistance in polymer membranes incorporating metal-organic framework nanocrystals

    NASA Astrophysics Data System (ADS)

    Bachman, Jonathan E.; Smith, Zachary P.; Li, Tao; Xu, Ting; Long, Jeffrey R.

    2016-08-01

    The implementation of membrane-based separations in the petrochemical industry has the potential to reduce energy consumption significantly relative to conventional separation processes. Achieving this goal, however, requires the development of new membrane materials with greater selectivity, permeability and stability than available at present. Here, we report composite materials consisting of nanocrystals of metal-organic frameworks dispersed within a high-performance polyimide, which can exhibit enhanced selectivity for ethylene over ethane, greater ethylene permeability and improved membrane stability. Our results suggest that framework-polymer interactions reduce chain mobility of the polymer while simultaneously boosting membrane separation performance. The increased stability, or plasticization resistance, is expected to improve membrane utility under real process conditions for petrochemical separations and natural gas purification. Furthermore, this approach can be broadly applied to numerous polymers that encounter aggressive environments, potentially making gas separations possible that were previously inaccessible to membranes.

  2. Enhanced ethylene separation and plasticization resistance in polymer membranes incorporating metal-organic framework nanocrystals.

    PubMed

    Bachman, Jonathan E; Smith, Zachary P; Li, Tao; Xu, Ting; Long, Jeffrey R

    2016-08-01

    The implementation of membrane-based separations in the petrochemical industry has the potential to reduce energy consumption significantly relative to conventional separation processes. Achieving this goal, however, requires the development of new membrane materials with greater selectivity, permeability and stability than available at present. Here, we report composite materials consisting of nanocrystals of metal-organic frameworks dispersed within a high-performance polyimide, which can exhibit enhanced selectivity for ethylene over ethane, greater ethylene permeability and improved membrane stability. Our results suggest that framework-polymer interactions reduce chain mobility of the polymer while simultaneously boosting membrane separation performance. The increased stability, or plasticization resistance, is expected to improve membrane utility under real process conditions for petrochemical separations and natural gas purification. Furthermore, this approach can be broadly applied to numerous polymers that encounter aggressive environments, potentially making gas separations possible that were previously inaccessible to membranes.

  3. Trapping gases in metal-organic frameworks with a selective surface molecular barrier layer

    PubMed Central

    Tan, Kui; Zuluaga, Sebastian; Fuentes, Erika; Mattson, Eric C.; Veyan, Jean-François; Wang, Hao; Li, Jing; Thonhauser, Timo; Chabal, Yves J.

    2016-01-01

    The main challenge for gas storage and separation in nanoporous materials is that many molecules of interest adsorb too weakly to be effectively retained. Instead of synthetically modifying the internal surface structure of the entire bulk—as is typically done to enhance adsorption—here we show that post exposure of a prototypical porous metal-organic framework to ethylenediamine can effectively retain a variety of weakly adsorbing molecules (for example, CO, CO2, SO2, C2H4, NO) inside the materials by forming a monolayer-thick cap at the external surface of microcrystals. Furthermore, this capping mechanism, based on hydrogen bonding as explained by ab initio modelling, opens the door for potential selectivity. For example, water molecules are shown to disrupt the hydrogen-bonded amine network and diffuse through the cap without hindrance and fully displace/release the retained small molecules out of the metal-organic framework at room temperature. These findings may provide alternative strategies for gas storage, delivery and separation. PMID:27958274

  4. Metal-organic framework with optimally selective xenon adsorption and separation.

    PubMed

    Banerjee, Debasis; Simon, Cory M; Plonka, Anna M; Motkuri, Radha K; Liu, Jian; Chen, Xianyin; Smit, Berend; Parise, John B; Haranczyk, Maciej; Thallapally, Praveen K

    2016-06-13

    Nuclear energy is among the most viable alternatives to our current fossil fuel-based energy economy. The mass deployment of nuclear energy as a low-emissions source requires the reprocessing of used nuclear fuel to recover fissile materials and mitigate radioactive waste. A major concern with reprocessing used nuclear fuel is the release of volatile radionuclides such as xenon and krypton that evolve into reprocessing facility off-gas in parts per million concentrations. The existing technology to remove these radioactive noble gases is a costly cryogenic distillation; alternatively, porous materials such as metal-organic frameworks have demonstrated the ability to selectively adsorb xenon and krypton at ambient conditions. Here we carry out a high-throughput computational screening of large databases of metal-organic frameworks and identify SBMOF-1 as the most selective for xenon. We affirm this prediction and report that SBMOF-1 exhibits by far the highest reported xenon adsorption capacity and a remarkable Xe/Kr selectivity under conditions pertinent to nuclear fuel reprocessing.

  5. A spin transition mechanism for cooperative adsorption in metal-organic frameworks.

    PubMed

    Reed, Douglas A; Keitz, Benjamin K; Oktawiec, Julia; Mason, Jarad A; Runčevski, Tomče; Xiao, Dianne J; Darago, Lucy E; Crocellà, Valentina; Bordiga, Silvia; Long, Jeffrey R

    2017-10-05

    Cooperative binding, whereby an initial binding event facilitates the uptake of additional substrate molecules, is common in biological systems such as haemoglobin. It was recently shown that porous solids that exhibit cooperative binding have substantial energetic benefits over traditional adsorbents, but few guidelines currently exist for the design of such materials. In principle, metal-organic frameworks that contain coordinatively unsaturated metal centres could act as both selective and cooperative adsorbents if guest binding at one site were to trigger an electronic transformation that subsequently altered the binding properties at neighbouring metal sites. Here we illustrate this concept through the selective adsorption of carbon monoxide (CO) in a series of metal-organic frameworks featuring coordinatively unsaturated iron(ii) sites. Functioning via a mechanism by which neighbouring iron(ii) sites undergo a spin-state transition above a threshold CO pressure, these materials exhibit large CO separation capacities with only small changes in temperature. The very low regeneration energies that result may enable more efficient Fischer-Tropsch conversions and extraction of CO from industrial waste feeds, which currently underutilize this versatile carbon synthon. The electronic basis for the cooperative adsorption demonstrated here could provide a general strategy for designing efficient and selective adsorbents suitable for various separations.

  6. Trapping gases in metal-organic frameworks with a selective surface molecular barrier layer

    NASA Astrophysics Data System (ADS)

    Tan, Kui; Zuluaga, Sebastian; Fuentes, Erika; Mattson, Eric C.; Veyan, Jean-François; Wang, Hao; Li, Jing; Thonhauser, Timo; Chabal, Yves J.

    2016-12-01

    The main challenge for gas storage and separation in nanoporous materials is that many molecules of interest adsorb too weakly to be effectively retained. Instead of synthetically modifying the internal surface structure of the entire bulk--as is typically done to enhance adsorption--here we show that post exposure of a prototypical porous metal-organic framework to ethylenediamine can effectively retain a variety of weakly adsorbing molecules (for example, CO, CO2, SO2, C2H4, NO) inside the materials by forming a monolayer-thick cap at the external surface of microcrystals. Furthermore, this capping mechanism, based on hydrogen bonding as explained by ab initio modelling, opens the door for potential selectivity. For example, water molecules are shown to disrupt the hydrogen-bonded amine network and diffuse through the cap without hindrance and fully displace/release the retained small molecules out of the metal-organic framework at room temperature. These findings may provide alternative strategies for gas storage, delivery and separation.

  7. Metal-organic framework with optimally selective xenon adsorption and separation

    NASA Astrophysics Data System (ADS)

    Banerjee, Debasis; Simon, Cory M.; Plonka, Anna M.; Motkuri, Radha K.; Liu, Jian; Chen, Xianyin; Smit, Berend; Parise, John B.; Haranczyk, Maciej; Thallapally, Praveen K.

    2016-06-01

    Nuclear energy is among the most viable alternatives to our current fossil fuel-based energy economy. The mass deployment of nuclear energy as a low-emissions source requires the reprocessing of used nuclear fuel to recover fissile materials and mitigate radioactive waste. A major concern with reprocessing used nuclear fuel is the release of volatile radionuclides such as xenon and krypton that evolve into reprocessing facility off-gas in parts per million concentrations. The existing technology to remove these radioactive noble gases is a costly cryogenic distillation; alternatively, porous materials such as metal-organic frameworks have demonstrated the ability to selectively adsorb xenon and krypton at ambient conditions. Here we carry out a high-throughput computational screening of large databases of metal-organic frameworks and identify SBMOF-1 as the most selective for xenon. We affirm this prediction and report that SBMOF-1 exhibits by far the highest reported xenon adsorption capacity and a remarkable Xe/Kr selectivity under conditions pertinent to nuclear fuel reprocessing.

  8. Trapping gases in metal-organic frameworks with a selective surface molecular barrier layer

    SciTech Connect

    Tan, Kui; Zuluaga, Sebastian; Fuentes, Erika; Mattson, Eric C.; Veyan, Jean-François; Wang, Hao; Li, Jing; Thonhauser, Timo; Chabal, Yves J.

    2016-12-13

    The main challenge for gas storage and separation in nanoporous materials is that many molecules of interest adsorb too weakly to be effectively retained. Instead of synthetically modifying the internal surface structure of the entire bulk—as is typically done to enhance adsorption—here we show that post exposure of a prototypical porous metal-organic framework to ethylenediamine can effectively retain a variety of weakly adsorbing molecules (for example, CO, CO2, SO2, C2H4, NO) inside the materials by forming a monolayer-thick cap at the external surface of microcrystals. Furthermore, this capping mechanism, based on hydrogen bonding as explained by ab initio modelling, opens the door for potential selectivity. For example, water molecules are shown to disrupt the hydrogen-bonded amine network and diffuse through the cap without hindrance and fully displace/release the retained small molecules out of the metal-organic framework at room temperature. Lastly, these findings may provide alternative strategies for gas storage, delivery and separation.

  9. Trapping gases in metal-organic frameworks with a selective surface molecular barrier layer

    DOE PAGES

    Tan, Kui; Zuluaga, Sebastian; Fuentes, Erika; ...

    2016-12-13

    The main challenge for gas storage and separation in nanoporous materials is that many molecules of interest adsorb too weakly to be effectively retained. Instead of synthetically modifying the internal surface structure of the entire bulk—as is typically done to enhance adsorption—here we show that post exposure of a prototypical porous metal-organic framework to ethylenediamine can effectively retain a variety of weakly adsorbing molecules (for example, CO, CO2, SO2, C2H4, NO) inside the materials by forming a monolayer-thick cap at the external surface of microcrystals. Furthermore, this capping mechanism, based on hydrogen bonding as explained by ab initio modelling, opensmore » the door for potential selectivity. For example, water molecules are shown to disrupt the hydrogen-bonded amine network and diffuse through the cap without hindrance and fully displace/release the retained small molecules out of the metal-organic framework at room temperature. Lastly, these findings may provide alternative strategies for gas storage, delivery and separation.« less

  10. Bimetallic Metal-Organic Frameworks for Controlled Catalytic Graphitization of Nanoporous Carbons

    NASA Astrophysics Data System (ADS)

    Tang, Jing; Salunkhe, Rahul R.; Zhang, Huabin; Malgras, Victor; Ahamad, Tansir; Alshehri, Saad M.; Kobayashi, Naoya; Tominaka, Satoshi; Ide, Yusuke; Kim, Jung Ho; Yamauchi, Yusuke

    2016-07-01

    Single metal-organic frameworks (MOFs), constructed from the coordination between one-fold metal ions and organic linkers, show limited functionalities when used as precursors for nanoporous carbon materials. Herein, we propose to merge the advantages of zinc and cobalt metals ions into one single MOF crystal (i.e., bimetallic MOFs). The organic linkers that coordinate with cobalt ions tend to yield graphitic carbons after carbonization, unlike those bridging with zinc ions, due to the controlled catalytic graphitization by the cobalt nanoparticles. In this work, we demonstrate a feasible method to achieve nanoporous carbon materials with tailored properties, including specific surface area, pore size distribution, degree of graphitization, and content of heteroatoms. The bimetallic-MOF-derived nanoporous carbon are systematically characterized, highlighting the importance of precisely controlling the properties of the carbon materials. This can be done by finely tuning the components in the bimetallic MOF precursors, and thus designing optimal carbon materials for specific applications.

  11. Bimetallic Metal-Organic Frameworks for Controlled Catalytic Graphitization of Nanoporous Carbons

    PubMed Central

    Tang, Jing; Salunkhe, Rahul R.; Zhang, Huabin; Malgras, Victor; Ahamad, Tansir; Alshehri, Saad M.; Kobayashi, Naoya; Tominaka, Satoshi; Ide, Yusuke; Kim, Jung Ho; Yamauchi, Yusuke

    2016-01-01

    Single metal-organic frameworks (MOFs), constructed from the coordination between one-fold metal ions and organic linkers, show limited functionalities when used as precursors for nanoporous carbon materials. Herein, we propose to merge the advantages of zinc and cobalt metals ions into one single MOF crystal (i.e., bimetallic MOFs). The organic linkers that coordinate with cobalt ions tend to yield graphitic carbons after carbonization, unlike those bridging with zinc ions, due to the controlled catalytic graphitization by the cobalt nanoparticles. In this work, we demonstrate a feasible method to achieve nanoporous carbon materials with tailored properties, including specific surface area, pore size distribution, degree of graphitization, and content of heteroatoms. The bimetallic-MOF-derived nanoporous carbon are systematically characterized, highlighting the importance of precisely controlling the properties of the carbon materials. This can be done by finely tuning the components in the bimetallic MOF precursors, and thus designing optimal carbon materials for specific applications. PMID:27471193

  12. The chemistry of metal-organic frameworks for CO2 capture, regeneration and conversion

    NASA Astrophysics Data System (ADS)

    Trickett, Christopher A.; Helal, Aasif; Al-Maythalony, Bassem A.; Yamani, Zain H.; Cordova, Kyle E.; Yaghi, Omar M.

    2017-08-01

    The carbon dioxide challenge is one of the most pressing problems facing our planet. Each stage in the carbon cycle — capture, regeneration and conversion — has its own materials requirements. Recent work on metal-organic frameworks (MOFs) demonstrated the potential and effectiveness of these materials in addressing this challenge. In this Review, we identify the specific structural and chemical properties of MOFs that have led to the highest capture capacities, the most efficient separations and regeneration processes, and the most effective catalytic conversions. The interior of MOFs can be designed to have coordinatively unsaturated metal sites, specific heteroatoms, covalent functionalization, other building unit interactions, hydrophobicity, porosity, defects and embedded nanoscale metal catalysts with a level of precision that is crucial for the development of higher-performance MOFs. To realize a total solution, it is necessary to use the precision of MOF chemistry to build more complex materials to address selectivity, capacity and conversion together in one material.

  13. In Silico Discovery of High Deliverable Capacity Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Bao, Yi; Martin, Richard; Simon, Cory; Haranczyk, Maciej; Smit, Berend; Deem, Michael; Michael W. Deem Team; Maciej Haranczyk Team; Berend Smit Team

    2015-03-01

    Metal organic frameworks (MOFs) are actively being explored as potential adsorbed natural gas storage materials for small vehicles. Experimental exploration of potential materials is limited by the throughput of synthetic chemistry. We here describe a computational methodology to complement and guide these experimental efforts. The method uses known chemical transformations in silico to identify MOFs with high methane deliverable capacity. The procedure explicitly considers synthesizability with geometric requirements on organic linkers. We efficiently search the composition and conformation space of organic linkers for nine MOF networks, finding 48 materials with higher predicted deliverable capacity (at 65 bar storage, 5.8 bar depletion, and 298 K) than MOF-5 in four of the nine networks. The best material has a predicted deliverable capacity 8% higher than that of MOF-5. US Department of Energy.

  14. Homochiral metal-organic frameworks and their application in chromatography enantioseparations.

    PubMed

    Peluso, Paola; Mamane, Victor; Cossu, Sergio

    2014-10-10

    The last frontier in the chiral stationary phases (CSPs) field for chromatography enantioseparations is represented by homochiral metal-organic frameworks (MOFs), a class of organic-inorganic hybrid materials built from metal-connecting nodes and organic-bridging ligands. The modular nature of these materials allows to design focused structures by combining properly metal, organic ligands and rigid polytopic spacers. Intriguingly, chiral ligands introduce molecular chirality in the MOF-network as well as homochirality in the secondary structure of materials (such as homohelicity) producing homochiral nets in a manner mimicking biopolymers (proteins, polysaccharides) which are characterized by a definite helical sense associated with the chirality of their building blocks (amino acids or sugars). Nowadays, robust and flexible materials characterized by high porosity and surface area became available by using preparative procedures typical of the so-called reticular synthesis. This review focuses on recent developments in the synthesis and applications of homochiral MOFs as supports for chromatography enantioseparations. Indeed, despite this field is in its infancy, interesting results have been produced and a critical overview of the 12 reported applications for gas chromatography (GC) and high-performance liquid chromatography (HPLC) can orient the reader approaching the field. Mechanistic aspects are shortly discussed and a view regarding future trends in this field is provided. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Metal-organic frameworks with functional pores for recognition of small molecules.

    PubMed

    Chen, Banglin; Xiang, Shengchang; Qian, Guodong

    2010-08-17

    Molecular recognition, an important process in biological and chemical systems, governs the diverse functions of a variety of enzymes and unique properties of some synthetic receptors. Because molecular recognition is based on weak interactions between receptors and substrates, the design and assembly of synthetic receptors to mimic biological systems and the development of novel materials to discriminate different substrates for selective recognition of specific molecules has proved challenging. The extensive research on synthetic receptors for molecular recognition, particularly on noncovalent complexes self-assembled by hydrogen bonding and metal-organic coordination, has revealed some underlying principles. In particular, these studies have demonstrated that the shapes of the supramolecular receptors play significant roles in their specific and selective recognition of substrates: receptors can offer concave surfaces that complement their convex targets. This Account describes our research to develop a synthetic molecular recognition platform using porous metal-organic frameworks (MOFs). These materials contain functional pores to direct their specific and unique recognition of small molecules through several types of interactions: van der Waals interactions of the framework surface with the substrate, metal-substrate interactions, and hydrogen bonding of the framework surface with the substrate. These materials have potential applications for gas storage, separation, and sensing. We demonstrate a simple strategy to construct a primitive cubic net of interpenetrated microporous MOFs from the self-assembly of the paddle-wheel clusters M(2)(CO(2))(4) (M = Cu(2+), Zn(2+), and Co(2+)) with two types of organic dicarboxylic acid and pillar bidentate linkers. This efficient method allows us to rationally tune the micropores to size-exclusively sort different small gas molecules, leading to the highly selective separation and purification of gases. By optimizing the

  16. Studies of gas adsorption in flexible Metal-Organic frameworks

    NASA Astrophysics Data System (ADS)

    Sircar, Sarmishtha

    Flexible Metal-Organic frameworks that exhibit a gate-opening (GO) adsorption mechanism have potential for gas separations and gas storage. The GO phenomenon occurs when molecular gates in the structure expand/contract in response to the activation/de-activation of a system variable e.g. temperature, pressure or gas. Sharp discontinuities in the isotherm leading to S-shapes and large adsorption-desorption hysteresis are typical of this phenomenon. This study investigates the kinetics and thermodynamics of the GO behavior by combining adsorption measurements and analytical modeling of adsorption kinetics and capacity as a function of adsorbate, GO pressure, and temperature. Basic understanding of GO mechanism will help harness GO-MOF's as adsorbents for gas separations and storage. Experiments were performed on two precharacterized MOFs with verified GO behavior. These are (1) Zn2(bpdc)2(bpee), which expands from a relative amorphous to crystalline structure and (2) Cu[(dhbc) 2(4,4f-bpy)]H2O, a mutually interdigitated 2-D structure (bpdc = biphenyldicarboxylate, bpee = 1,2]bipyridylethene; DMF = N,N-dimethyl formamide, dhbc= 2,5-dihydroxybenzoic acid, bpy=bipyridine). Both sub- and super-critical adsorption data were collected using three adsorption units: a standard low-pressure volumetric adsorption unit, a commercial high-pressure gravimetric analyzer and a custom-built high-pressure differential volumetric unit. Collected laboratory data were combined with published adsorption rate and isotherm data for analysis to broaden the range of data collection. The accuracy of the high-pressure differential unit was improved by over 300-fold by changing analytical methods of processing data to establish a reliable null correction. A pronounced effect of the allowed experimental time was found at cryogenic temperatures on (1). Tightening the stability criteria used by the adsorption equipment to determine equilibration increased the experimental time from the order of

  17. Nanoporous metal organic frameworks as hybrid polymer-metal composites for drug delivery and biomedical applications.

    PubMed

    Beg, Sarwar; Rahman, Mahfoozur; Jain, Atul; Saini, Sumant; Midoux, Patrick; Pichon, Chantal; Ahmad, Farhan Jalees; Akhter, Sohail

    2017-04-01

    Metal organic frameworks (MOFs), porous hybrid polymer-metal composites at the nanoscale, are recent innovations in the field of chemistry; they are novel polymeric materials with diverse biomedical applications. MOFs are nanoporous materials, consisting of metal ions linked together by organic bridging ligands. The unique physical and chemical characteristics of MOFs have attracted wider attention from the scientific community, exploring their utility in the field of material science, biology, nanotechnology and drug delivery. The practical feasibility of MOFs is possible owing to their abilities for biodegradability, excellent porosity, high loading capacity, ease of surface modification, among others. In this regard, this review provides an account of various types of MOFs, their physiochemical characteristics and use in diverse disciplines of biomedical sciences - with special emphasis on drug delivery and theranostics. Moreover, this review also highlights the stability and toxicity issues of MOFs, along with their market potential for biomedical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Metal-Organic Framework Thin Films as Stationary Phases in Microfabricated Gas-Chromatography Columns.

    SciTech Connect

    Read, Douglas; Sillerud, Colin Halliday

    2016-01-01

    The overarching goal of this project is to integrate Sandia's microfabricated gas-chromatography ( GC) columns with a stationary phase material that is capable of retaining high-volatility chemicals and permanent gases. The successful integration of such a material with GCs would dramatically expand the repertoire of detectable compounds for Sandia's various microanalysis systems. One such promising class of candidate materials is metal-organic frameworks (MOFs). In this report we detail our methods for controlled deposition of HKUST-1 MOF stationary phases within GC columns. We demonstrate: the chromatographic separation of natural gas; a method for determining MOF film thickness from chromatography alone; and the first-reported GC x GC separation of natural gas -- in general -- let alone for two disparate MOF stationary phases. In addition we determine the fundamental thermodynamic constant for mass sorption, the partition coefficient, for HKUST-1 and several light hydrocarbons and select toxic industrial chemicals.

  19. Stimuli-Responsive Metal-Organic Frameworks with Photoswitchable Azobenzene Side Groups.

    PubMed

    Kanj, Anemar Bruno; Müller, Kai; Heinke, Lars

    2017-07-31

    Metal-organic frameworks (MOFs) are nanoporous, crystalline hybrid materials, which enable various functionalities by incorporating functional organic molecules. By using organic linker molecules that possess photoswitchable azobenzene side groups, the remote control over certain properties was introduced to MOFs. Different MOF materials in the form of powders and thin films have been used to demonstrate the photoswitching. The applications of these stimuli-responsive nanoporous solids range from switching the adsorption capacity of various gases over remote-controlled release of guest molecules to continuously tunable membrane separation of molecular mixtures. A particular focus of this review is the effect of the azobenzene photoswitching on the host-guest interaction, enabling smart applications of the material. Steric hindrance, which may suppress the photoswitching in some MOF structures, is also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Tailoring porosity and rotational dynamics in a series of octacarboxylate metal-organic frameworks.

    PubMed

    Moreau, Florian; Kolokolov, Daniil I; Stepanov, Alexander G; Easun, Timothy L; Dailly, Anne; Lewis, William; Blake, Alexander J; Nowell, Harriott; Lennox, Matthew J; Besley, Elena; Yang, Sihai; Schröder, Martin

    2017-03-21

    Modulation and precise control of porosity of metal-organic frameworks (MOFs) is of critical importance to their materials function. Here we report modulation of porosity for a series of isoreticular octacarboxylate MOFs, denoted MFM-180 to MFM-185, via a strategy of selective elongation of metal-organic cages. Owing to the high ligand connectivity, these MOFs do not show interpenetration, and are robust structures that have permanent porosity. Interestingly, activated MFM-185a shows a high Brunauer-Emmett-Teller (BET) surface area of 4,734 m(2) g(-1) for an octacarboxylate MOF. These MOFs show remarkable CH4 and CO2 adsorption properties, notably with simultaneously high gravimetric and volumetric deliverable CH4 capacities of 0.24 g g(-1) and 163 vol/vol (298 K, 5-65 bar) recorded for MFM-185a due to selective elongation of tubular cages. The dynamics of molecular rotors in deuterated MFM-180a-d16 and MFM-181a-d16 were investigated by variable-temperature (2)H solid-state NMR spectroscopy to reveal the reorientation mechanisms within these materials. Analysis of the flipping modes of the mobile phenyl groups, their rotational rates, and transition temperatures paves the way to controlling and understanding the role of molecular rotors through design of organic linkers within porous MOF materials.

  1. Tailoring porosity and rotational dynamics in a series of octacarboxylate metal-organic frameworks

    PubMed Central

    Moreau, Florian; Kolokolov, Daniil I.; Stepanov, Alexander G.; Easun, Timothy L.; Dailly, Anne; Blake, Alexander J.; Nowell, Harriott; Lennox, Matthew J.; Yang, Sihai; Schröder, Martin

    2017-01-01

    Modulation and precise control of porosity of metal-organic frameworks (MOFs) is of critical importance to their materials function. Here we report modulation of porosity for a series of isoreticular octacarboxylate MOFs, denoted MFM-180 to MFM-185, via a strategy of selective elongation of metal-organic cages. Owing to the high ligand connectivity, these MOFs do not show interpenetration, and are robust structures that have permanent porosity. Interestingly, activated MFM-185a shows a high Brunauer–Emmett–Teller (BET) surface area of 4,734 m2 g−1 for an octacarboxylate MOF. These MOFs show remarkable CH4 and CO2 adsorption properties, notably with simultaneously high gravimetric and volumetric deliverable CH4 capacities of 0.24 g g−1 and 163 vol/vol (298 K, 5–65 bar) recorded for MFM-185a due to selective elongation of tubular cages. The dynamics of molecular rotors in deuterated MFM-180a-d16 and MFM-181a-d16 were investigated by variable-temperature 2H solid-state NMR spectroscopy to reveal the reorientation mechanisms within these materials. Analysis of the flipping modes of the mobile phenyl groups, their rotational rates, and transition temperatures paves the way to controlling and understanding the role of molecular rotors through design of organic linkers within porous MOF materials. PMID:28280097

  2. Shock resistance of metal-organic framework Cu-1,3,5-benzenetricarboxylate with and without ferrocene inclusion

    NASA Astrophysics Data System (ADS)

    Wei, Q.; Xu, H. W.; Yu, X. H.; Shimada, T.; Rearick, M. S.; Hickmott, D. D.; Zhao, Y. S.; Luo, S. N.

    2011-09-01

    A first-of-its-kind study on the shock response of a metal-organic framework (MOF) material to planar impact is reported. MOF Cu-1,3,5-benzenetricarboxylate (Cu-BTC) without and with ferrocene inclusion show anisotropic structural collapse under shock loading. The shock resistance of the Cu-BTC framework is enhanced drastically (by a factor of six) via molecular-level inclusion of ferrocene into the pore structures.

  3. Shock Resistance of Metal-Organic Framework Cu-1,3,5-Benzenetricarboxylate with and without Ferrocene Inclusion

    NASA Astrophysics Data System (ADS)

    Wei, Q.; Xu, H. W.; Luo, S. N.

    2011-06-01

    A first-of-the-kind study on the dynamic response of a metal-organic framework (MOF) material to impulsive shock wave loading is reported. MOF Cu-1,3,5-benzenetricarboxylate (Cu-BTC) without and with ferrocene inclusion show anisotropic structural collapse under shock loading, likely due to the elastic anisotropy of the network structure. The shock resistance of Cu-BTC framework is enhanced drastically (by a factor of six) via including ferrocene into the pore structures.

  4. The modulator driven polymorphism of Zr(IV) based metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Drache, Franziska; Bon, Volodymyr; Senkovska, Irena; Getzschmann, Jürgen; Kaskel, Stefan

    2017-01-01

    The reaction of ZrCl4 and 2,5-thiophenedicarboxylic acid (H2tdc) in the presence of trifluoroacetic acid (Htfa) as modulator results in the formation of the new metal-organic framework (MOF) named DUT-126 (DUT = Dresden University of Technology). The nature and concentration of modulators are found to be decisive synthetic parameters affecting the topology of the formed product. DUT-126 (hbr) extends the series of polymorphs differing in topology, namely DUT-67 (reo), DUT-68 (bon) and DUT-69 (bct) to four, where DUT-67 and DUT-68 show the same eight-connected secondary building units as in DUT-126. In DUT-126, linker molecules have a peculiar orientation, resulting in hbr topology, which is described for the first time in this work for MOFs. DUT-126 contains three pore types, including two micropores surrounding mesoporous channels. DUT-126 is stable against hydrolysis and features permanent porosity with a specific surface area of 1297 m2 g-1 and a total pore volume of 0.48 cm3 g-1, calculated from the nitrogen physisorption isotherm measured at 77 K. This article is part of the themed issue 'Coordination polymers and metal-organic frameworks: materials by design'.

  5. Magnetoelectric coupling in the paramagnetic state of a metal-organic framework

    PubMed Central

    Wang, W.; Yan, L. -Q.; Cong, J. -Z.; Zhao, Y. -L.; Wang, F.; Shen, S. -P.; Zou, T.; Zhang, D.; Wang, S. -G.; Han, X. -F.; Sun, Y.

    2013-01-01

    Although the magnetoelectric effects - the mutual control of electric polarization by magnetic fields and magnetism by electric fields, have been intensively studied in a large number of inorganic compounds and heterostructures, they have been rarely observed in organic materials. Here we demonstrate magnetoelectric coupling in a metal-organic framework [(CH3)2NH2]Mn(HCOO)3 which exhibits an order-disorder type of ferroelectricity below 185 K. The magnetic susceptibility starts to deviate from the Curie-Weiss law at the paraelectric-ferroelectric transition temperature, suggesting an enhancement of short-range magnetic correlation in the ferroelectric state. Electron spin resonance study further confirms that the magnetic state indeed changes following the ferroelectric phase transition. Inversely, the ferroelectric polarization can be improved by applying high magnetic fields. We interpret the magnetoelectric coupling in the paramagnetic state in the metal-organic framework as a consequence of the magnetoelastic effect that modifies both the superexchange interaction and the hydrogen bonding. PMID:23778158

  6. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture

    PubMed Central

    Shekhah, Osama; Belmabkhout, Youssef; Chen, Zhijie; Guillerm, Vincent; Cairns, Amy; Adil, Karim; Eddaoudi, Mohamed

    2014-01-01

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 44 square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 Å for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials. PMID:24964404

  7. Study of the Inorganic Substitution in a Functionalized UiO-66 Metal-Organic Framework

    NASA Astrophysics Data System (ADS)

    Yasin, Alhassan Salman

    Metal-Organic Frameworks (MOFs) have received considerable attention and fast development in the past few years. These materials have demonstrated a wide range of applications due to their porosity, tailorability of optical properties, and chemical selectivity. This report catalogs common MOF designs based on application and diversity in various fields, as well as conduct an in-depth study of inorganic substitution in a functionalized MOF. This study investigates the band gap modulation in response to inorganic ion substitution within a thermally stable UiO-66 Metal-Organic Framework (MOF). A combination of density functional theory (DFT) predictions in conjunction with experimental predictions were used to map out the complete composition space for three inorganic ions (Zr, Hf, Ti) and three functional groups. The three functional groups include an amino group (NH2), a nitro group (NO2), and a hydrogenated case (H). The smallest determined band gap was for a partially substituted UiO-66(Ti5Zr1)-NH2 resulting in 2.60eV. Theoretical findings sup-port that Ti can be fully substituted within the lattice resulting in a predicted band gap as low as 1.62(2.77)eV. Band gap modulation was reasoned to be a result of a mid gap state introduced through the amino functionalization and HOMO shifting as a result of increased binding of the Ti-O-C bonds.

  8. The modulator driven polymorphism of Zr(IV) based metal-organic frameworks.

    PubMed

    Drache, Franziska; Bon, Volodymyr; Senkovska, Irena; Getzschmann, Jürgen; Kaskel, Stefan

    2017-01-13

    The reaction of ZrCl4 and 2,5-thiophenedicarboxylic acid (H2tdc) in the presence of trifluoroacetic acid (Htfa) as modulator results in the formation of the new metal-organic framework (MOF) named DUT-126 (DUT = Dresden University of Technology). The nature and concentration of modulators are found to be decisive synthetic parameters affecting the topology of the formed product. DUT-126 ( HBR: ) extends the series of polymorphs differing in topology, namely DUT-67 ( REO: ), DUT-68 ( BON: ) and DUT-69 ( BCT: ) to four, where DUT-67 and DUT-68 show the same eight-connected secondary building units as in DUT-126. In DUT-126, linker molecules have a peculiar orientation, resulting in HBR: topology, which is described for the first time in this work for MOFs. DUT-126 contains three pore types, including two micropores surrounding mesoporous channels. DUT-126 is stable against hydrolysis and features permanent porosity with a specific surface area of 1297 m(2) g(-1) and a total pore volume of 0.48 cm(3) g(-1), calculated from the nitrogen physisorption isotherm measured at 77 K.This article is part of the themed issue 'Coordination polymers and metal-organic frameworks: materials by design'.

  9. Efficient methods for screening of metal organic framework membranes for gas separations using atomically detailed models.

    PubMed

    Keskin, Seda; Sholl, David S

    2009-10-06

    Metal organic frameworks (MOFs) define a diverse class of nanoporous materials having potential applications in adsorption-based and membrane-based gas separations. We have previously used atomically detailed models to predict the performance of MOFs for membrane-based separations of gases, but these calculations require considerable computational resources and time. Here, we introduce an efficient approximate method for screening MOFs based on atomistic models that will accelerate the modeling of membrane applications. The validity of this approximate method is examined by comparison with detailed calculations for CH4/H2, CO2/CH4, and CO2/H2 mixtures at room temperature permeating through IRMOF-1 and CuBTC membranes. These results allow us to hypothesize a connection between two computationally efficient correlations predicting mixture adsorption and mixture self-diffusion properties and the validity of our approximate screening method. We then apply our model to six additional MOFs, IRMOF-8, -9, -10, and -14, Zn(bdc)(ted)0.5, and COF-102, to examine the effect of chemical diversity and interpenetration on the performance of metal organic framework membranes for light gas separations.

  10. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture

    NASA Astrophysics Data System (ADS)

    Shekhah, Osama; Belmabkhout, Youssef; Chen, Zhijie; Guillerm, Vincent; Cairns, Amy; Adil, Karim; Eddaoudi, Mohamed

    2014-06-01

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 44 square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 Å for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials.

  11. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture.

    PubMed

    Shekhah, Osama; Belmabkhout, Youssef; Chen, Zhijie; Guillerm, Vincent; Cairns, Amy; Adil, Karim; Eddaoudi, Mohamed

    2014-06-25

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 4(4) square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 Å for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials.

  12. Rational design of metal-organic frameworks with anticipated porosities and functionalities

    SciTech Connect

    Zhang, MW; Bosch, M; Gentle, T; Zhou, HC

    2014-01-01

    Metal-organic frameworks have emerged as a new category of porous materials that have intriguing structures and diverse applications. Even though the early discovery of new MOFs appears to be serendipitous, much effort has been made to reveal their structure-property relationships for the purpose of rationally designing novel frameworks with expected properties. Until now, much progress has been made to rationalize the design and synthesis of MOFs. This highlight review will outline the recent advances on this topic from both our and other groups and provide a systematic overview of different methods for the rational design of MOFs with desired porosities and functionalities. In this review, we will categorize the recent efforts for rational MOF design into two different approaches: a structural approach and a functional approach.

  13. A Homochiral Multifunctional Metal-Organic Framework with Rod-Shaped Secondary Building Units

    PubMed Central

    Cai, Kun; Zhao, Nian; Zhang, Ning; Sun, Fu-Xing; Zhao, Qing; Zhu, Guang-Shan

    2017-01-01

    A new homochiral multifunctional metal-organic framework, [Zn2(CTBA)2·H2O] (JUC-112), was synthesized under solvothermal conditions, through the design of chiral ligand 4-(3-carboxy-2,2,3-trimethylcyclopentanecarboxamido) benzoic acid (H2CTBA) based on camphoric acid as building block. The crystal structure of the new material is a 2-dimensional (2D) chiral layer packed with infinite rod-shaped secondary building units (SBUs). The homochiral framework was identified by circular dichroism (CD) spectrum. Thermogravimetric measurement indicates its high thermal stability up to 450 °C. In addition, JUC-112 exhibits the capability of separating water from alcohols, second-order nonlinear optical effect, and photoluminescence. PMID:28430135

  14. Communication: Enthalpy relaxation in a metal-organic zeolite imidazole framework (ZIF-4) glass-former

    NASA Astrophysics Data System (ADS)

    Xu, Di; Liu, Yingdan; Tian, Yongjun; Wang, Li-Min

    2017-03-01

    Amorphization in metal-organic framework materials initiated by the collapsed crystal offers new access to glasses; however, the understanding of such glasses remains to be clarified. Here, we studied the glass transition thermodynamics and kinetics in a zeolitic imidazolate framework ZIF-4 utilizing enthalpy relaxation measurements. The calorimetric glass transition profile and relaxation behaviors in ZIF-4 are found to reproduce the basic features and correlations manifested by conventional melt-quenched glasses. A comparison with various melt-quenched glasses suggests that the low fragility of ZIF-4 is ascribed to the low thermal-pressure coefficient due to the directional tetrahedral bond, partly leading to the low vibrational entropy in the melt-crystal entropy difference.

  15. Liquid- and Gas-Phase Diffusion of Ferrocene in Thin Films of Metal-Organic Frameworks

    PubMed Central

    Zhou, Wencai; Wöll, Christof; Heinke, Lars

    2015-01-01

    The mass transfer of the guest molecules in nanoporous host materials, in particular in metal-organic frameworks (MOFs), is among the crucial features of their applications. By using thin surface-mounted MOF films in combination with a quartz crystal microbalance (QCM), the diffusion of ferrocene vapor and of ethanolic and hexanic ferrocene solution in HKUST-1 was investigated. For the first time, liquid- and gas-phase diffusion in MOFs was compared directly in the identical sample. The diffusion coefficients are in the same order of magnitude (~10−16 m2·s−1), whereas the diffusion coefficient of ferrocene in the empty framework is roughly 3-times smaller than in the MOF which is filled with ethanol or n-hexane.

  16. Zinc Imidazolate Metal-Organic Frameworks (ZIF-8) for Electrochemical Reduction of CO2 to CO.

    PubMed

    Wang, Yulin; Hou, Pengfei; Wang, Zhuo; Kang, Peng

    2017-08-01

    Metal-organic frameworks (MOFs) are regarded as promising materials for CO2 adsorption, which is an important step in CO2 electrochemical reduction. In this work, zeolitic imidazolate framework (ZIF-8) nanomaterials were synthesized with various zinc sources and used as electrocatalysts for CO2 reduction to CO. Among them, ZIF-8, prepared using ZnSO4 , delivers the best catalytic activity towards CO2 electroreduction, with 65 % CO yield. The main catalytic center can be attributed to the discrete Zn nodes in ZIF-8. Electrolytes are important in increasing the CO selectivity, and NaCl is the best suitable electrolyte due to facile anion exchange. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Porous Metal-Organic Frameworks for Gas Storage and Separation: What, How, and Why?

    PubMed

    Li, Bin; Wen, Hui-Min; Zhou, Wei; Chen, Banglin

    2014-10-16

    Metal-organic frameworks (MOFs) have been emerging as promising multifunctional materials and have shown particularly useful applications for gas storage and separation. We have briefly outlined the early development of this very active research field to provide us a clear picture on what are MOFs and how the research endeavor has been initiated and explored. Following that, we have demonstrated why MOFs are so unique for gas storage and separation: high porosities, tunable framework structures, and immobilized functional sites to fully make use of pore space for gas storage, to optimize their sieving effects, and to differentiate their interactions with gas molecules. Finally, we have provided a perspective on further development of porous MOFs for gas storage and separation.

  18. Communication: Enthalpy relaxation in a metal-organic zeolite imidazole framework (ZIF-4) glass-former.

    PubMed

    Xu, Di; Liu, Yingdan; Tian, Yongjun; Wang, Li-Min

    2017-03-28

    Amorphization in metal-organic framework materials initiated by the collapsed crystal offers new access to glasses; however, the understanding of such glasses remains to be clarified. Here, we studied the glass transition thermodynamics and kinetics in a zeolitic imidazolate framework ZIF-4 utilizing enthalpy relaxation measurements. The calorimetric glass transition profile and relaxation behaviors in ZIF-4 are found to reproduce the basic features and correlations manifested by conventional melt-quenched glasses. A comparison with various melt-quenched glasses suggests that the low fragility of ZIF-4 is ascribed to the low thermal-pressure coefficient due to the directional tetrahedral bond, partly leading to the low vibrational entropy in the melt-crystal entropy difference.

  19. Solvent-Induced Cadmium(II) Metal-Organic Frameworks with Adjustable Guest-Evacuated Porosity: Application in the Controllable Assembly of MOF-Derived Porous Carbon Materials for Supercapacitors.

    PubMed

    Yue, Man-Li; Jiang, Yi-Fan; Zhang, Lin; Yu, Cheng-Yan; Zou, Kang-Yu; Li, Zuo-Xi

    2017-08-07

    In this work, five new cadmium metal-organic frameworks (Cd-MOFs 1-5) have been synthesized from solvothermal reactions of Cd(NO3 )2 ⋅4 H2 O with isophthalic acid and 1,4-bis(imidazol-1-yl)-benzene under different solvent systems of CH3 OH, C2 H5 OH, (CH3 )2 CHOH, DMF, and N-methyl-2-pyrrolidone (NMP), respectively. Cd-MOF 1 shows a 3D diamondoid framework with 1D rhombic and hexagonal channels, and the porosity is 12.9 %. Cd-MOF 2 exhibits a 2D (4,4) layer with a 1D parallelogram channel and porosity of 23.6 %. Cd-MOF 3 has an 8-connected dense network with the Schäfli symbol of [4(24) ⋅6(4) ] based on the Cd6 cluster. Cd-MOFs 4-5 are isomorphous, and display an absolutely double-bridging 2D (4,4) layer with 1D tetragonal channels and porosities of 29.2 and 28.2 %, which are occupied by DMF and NMP molecules, respectively. Followed by the calcination-thermolysis procedure, Cd-MOFs 1-5 are employed as precursors to prepare MOF-derived porous carbon materials (labeled as PC-me, PC-eth, PC-ipr, PC-dmf and PC-nmp), which have the BET specific surface area of 23, 51, 10, 122, and 96 m(2)  g(-1) , respectively. The results demonstrate that the specific surface area of PCs is tuned by the porosity of Cd-MOFs, where the later is highly dependent on the solvent. Thereby, the specific surface area of PCs could be adjusted by the solvent used in the synthese of MOF precusors. Significantly, PCs have been further activated by KOH to obtain activated carbon materials (APCs), which possess even higher specific surface area and larger porosity. After a series of characterization and electrochemical investigations, the APC-dmf electrode exhibits the best porous properties and largest specific capacitances (153 F g(-1) at 5 mV s(-1) and 156 F g(-1) at 0.5 Ag(-1) ). Meanwhile, the APC-dmf electrode shows excellent cycling stability (ca. 84.2 % after 5000 cycles at 1 Ag(-1) ), which can be applied as a suitable electrode material for

  20. Transformation of metal-organic framework to polymer gel by cross-linking the organic ligands preorganized in metal-organic framework.

    PubMed

    Ishiwata, Takumi; Furukawa, Yuki; Sugikawa, Kouta; Kokado, Kenta; Sada, Kazuki

    2013-04-10

    Until now, seamless fusion of metal-organic frameworks (MOFs) and covalently cross-linked polymer gels (PG) at molecular level has been extremely rare, since these two matters have been regarded as opposite, that is, hard versus soft. In this report, we demonstrate transformation of cubic MOF crystals to PG via inner cross-linking of the organic linkers in the void space of MOF, followed by decomposition of the metal coordination. The obtained PG behaved as a polyelectrolyte gel, indicating the high content of ionic groups inside. Metal ions were well adsorbed in the PG due to its densely packed carboxylate groups. A chimera-type hybrid material consisting of MOF and PG was obtained by partial hydrolysis of resulting cross-linked MOF. The shape of resulting PG network well reflected the crystal structure of MOF employed as a template. Our results will connect the two different network materials that have been ever studied in the two different fields to provide new soft and hard hybrid materials, and the unique copolymerization in the large void space of the MOF will open a new horizon toward "ideal network polymers" never prepared before now.

  1. Metal-organic frameworks for thermoelectric energy-conversion applications

    SciTech Connect

    Talin, Albert Alec; Jones, Reese E.; Hopkins, Patrick E.

    2016-11-07

    Motivated by low cost, low toxicity, mechanical flexibility, and conformability over complex shapes, organic semiconductors are currently being actively investigated as thermoelectric (TE) materials to replace the costly, brittle, and non-eco-friendly inorganic TEs for near-ambient-temperature applications. Metal–organic frameworks (MOFs) share many of the attractive features of organic polymers, including solution processability and low thermal conductivity. A potential advantage of MOFs and MOFs with guest molecules (Guest@MOFs) is their synthetic and structural versatility, which allows both the electronic and geometric structure to be tuned through the choice of metal, ligand, and guest molecules. This could solve the long-standing challenge of finding stable, high-TE-performance n-type organic semiconductors, as well as promote high charge mobility via the long-range crystalline order inherent in these materials. In this paper, we review recent advances in the synthesis of MOF and Guest@MOF TEs and discuss how the Seebeck coefficient, electrical conductivity, and thermal conductivity could be tuned to further optimize TE performance.

  2. Metal-organic frameworks for thermoelectric energy-conversion applications

    DOE PAGES

    Talin, Albert Alec; Jones, Reese E.; Hopkins, Patrick E.

    2016-11-07

    Motivated by low cost, low toxicity, mechanical flexibility, and conformability over complex shapes, organic semiconductors are currently being actively investigated as thermoelectric (TE) materials to replace the costly, brittle, and non-eco-friendly inorganic TEs for near-ambient-temperature applications. Metal–organic frameworks (MOFs) share many of the attractive features of organic polymers, including solution processability and low thermal conductivity. A potential advantage of MOFs and MOFs with guest molecules (Guest@MOFs) is their synthetic and structural versatility, which allows both the electronic and geometric structure to be tuned through the choice of metal, ligand, and guest molecules. This could solve the long-standing challenge of findingmore » stable, high-TE-performance n-type organic semiconductors, as well as promote high charge mobility via the long-range crystalline order inherent in these materials. In this paper, we review recent advances in the synthesis of MOF and Guest@MOF TEs and discuss how the Seebeck coefficient, electrical conductivity, and thermal conductivity could be tuned to further optimize TE performance.« less

  3. High Methane Storage Capacity in Aluminum Metal-Organic Frameworks

    SciTech Connect

    Gándara, Felipe; Furukawa, Hiroyasu; Lee, Seungkyu; Yaghi, Omar M.

    2014-08-14

    The use of porous materials to store natural gas in vehicles requires large amounts of methane per unit of volume. Here we report the synthesis, crystal structure and methane adsorption properties of two new aluminum metal–organic frameworks, MOF-519 and MOF-520. Both materials exhibit permanent porosity and high methane volumetric storage capacity: MOF-519 has a volumetric capacity of 200 and 279 cm3 cm–3 at 298 K and 35 and 80 bar, respectively, and MOF-520 has a volumetric capacity of 162 and 231 cm3 cm–3 under the same conditions. Furthermore, MOF-519 exhibits an exceptional working capacity, being able to deliver a large amount of methane at pressures between 5 and 35 bar, 151 cm3 cm–3, and between 5 and 80 bar, 230 cm3 cm–3.

  4. Interpenetration as a mechanism for negative thermal expansion in the metal-organic framework Cu3(btb)2 (MOF-14).

    PubMed

    Wu, Yue; Peterson, Vanessa K; Luks, Emily; Darwish, Tamim A; Kepert, Cameron J

    2014-05-12

    Metal-organic framework materials (MOFs) have recently been shown in some cases to exhibit strong negative thermal expansion (NTE) behavior, while framework interpenetration has been found to reduce NTE in many materials. Using powder and single-crystal diffraction methods we investigate the thermal expansion behavior of interpenetrated Cu3(btb)2 (MOF-14) and find that it exhibits an anomalously large NTE effect. Temperature-dependent structural analysis shows that, contrary to other interpenetrated materials, in MOF-14 the large positive thermal expansion of weak interactions that hold the interpenetrating networks together results in a low-energy contractive distortion of the overall framework structure, demonstrating a new mechanism for NTE.

  5. Synthesis and characterization of boric acid mediated metal-organic frameworks based on trimesic acid and terephthalic acid

    NASA Astrophysics Data System (ADS)

    Ozer, Demet; Köse, Dursun A.; Şahin, Onur; Oztas, Nursen Altuntas

    2017-08-01

    The new metal-organic framework materials based on boric acid reported herein. Sodium and boron containing metal-organic frameworks were synthesized by one-pot self-assembly reaction in the presence of trimesic acid and terephthalic acid in water/ethanol solution. Boric acid is a relatively cheap boron source and boric acid mediated metal-organic framework prepared mild conditions compared to the other boron source based metal-organic framework. The synthesized compounds were characterized by FT-IR, p-XRD, TGA/DTA, elemental analysis, 13C-MAS NMR, 11B-NMR and single crystal measurements. The molecular formulas of compounds were estimated as C18H33B2Na5O28 and C8H24B2Na2O17 according to the structural analysis. The obtained complexes were thermally stable. Surface properties of inorganic polymer complexes were investigated by BET analyses and hydrogen storage properties of compound were also calculated.

  6. A Review on Breathing Behaviors of Metal-Organic-Frameworks (MOFs) for Gas Adsorption.

    PubMed

    Alhamami, Mays; Doan, Huu; Cheng, Chil-Hung

    2014-04-21

    Metal-organic frameworks (MOFs) are a new class of microporous materials that possess framework flexibility, large surface areas, "tailor-made" framework functionalities, and tunable pore sizes. These features empower MOFs superior performances and broader application spectra than those of zeolites and phosphine-based molecular sieves. In parallel with designing new structures and new chemistry of MOFs, the observation of unique breathing behaviors upon adsorption of gases or solvents stimulates their potential applications as host materials in gas storage for renewable energy. This has attracted intense research energy to understand the causes at the atomic level, using in situ X-ray diffraction, calorimetry, Fourier transform infrared spectroscopy, and molecular dynamics simulations. This article is developed in the following order: first to introduce the definition of MOFs and the observation of their framework flexibility. Second, synthesis routes of MOFs are summarized with the emphasis on the hydrothermal synthesis, owing to the environmental-benign and economically availability of water. Third, MOFs exhibiting breathing behaviors are summarized, followed by rationales from thermodynamic viewpoint. Subsequently, effects of various functionalities on breathing behaviors are appraised, including using post-synthetic modification routes. Finally, possible framework spatial requirements of MOFs for yielding breathing behaviors are highlighted as the design strategies for new syntheses.

  7. A Review on Breathing Behaviors of Metal-Organic-Frameworks (MOFs) for Gas Adsorption

    PubMed Central

    Alhamami, Mays; Doan, Huu; Cheng, Chil-Hung

    2014-01-01

    Metal-organic frameworks (MOFs) are a new class of microporous materials that possess framework flexibility, large surface areas, “tailor-made” framework functionalities, and tunable pore sizes. These features empower MOFs superior performances and broader application spectra than those of zeolites and phosphine-based molecular sieves. In parallel with designing new structures and new chemistry of MOFs, the observation of unique breathing behaviors upon adsorption of gases or solvents stimulates their potential applications as host materials in gas storage for renewable energy. This has attracted intense research energy to understand the causes at the atomic level, using in situ X-ray diffraction, calorimetry, Fourier transform infrared spectroscopy, and molecular dynamics simulations. This article is developed in the following order: first to introduce the definition of MOFs and the observation of their framework flexibility. Second, synthesis routes of MOFs are summarized with the emphasis on the hydrothermal synthesis, owing to the environmental-benign and economically availability of water. Third, MOFs exhibiting breathing behaviors are summarized, followed by rationales from thermodynamic viewpoint. Subsequently, effects of various functionalities on breathing behaviors are appraised, including using post-synthetic modification routes. Finally, possible framework spatial requirements of MOFs for yielding breathing behaviors are highlighted as the design strategies for new syntheses. PMID:28788614

  8. High proton conduction in a chiral ferromagnetic metal-organic quartz-like framework.

    PubMed

    Pardo, Emilio; Train, Cyrille; Gontard, Geoffrey; Boubekeur, Kamal; Fabelo, Oscar; Liu, Hongbo; Dkhil, Brahim; Lloret, Francesc; Nakagawa, Kosuke; Tokoro, Hiroko; Ohkoshi, Shin-ichi; Verdaguer, Michel

    2011-10-05

    A complex-as-ligand strategy to get a multifunctional molecular material led to a metal-organic framework with the formula (NH(4))(4)[MnCr(2)(ox)(6)]·4H(2)O. Single-crystal X-ray diffraction revealed that the anionic bimetallic coordination network adopts a chiral three-dimensional quartz-like architecture. It hosts ammonium cations and water molecules in functionalized channels. In addition to ferromagnetic ordering below T(C) = 3.0 K related to the host network, the material exhibits a very high proton conductivity of 1.1 × 10(-3) S cm(-1) at room temperature due to the guest molecules.

  9. Scalable synthesis and post-modification of a mesoporous metal-organic framework called NU-1000

    DOE PAGES

    Wang, Timothy C.; Vermeulen, Nicolaas A.; Kim, In Soo; ...

    2015-12-17

    The synthesis of NU-1000, a mesoporous metal-organic framework (MOF), can be conducted efficiently on a multigram scale from inexpensive starting materials. NU-1000 has been reported as an excellent candidate for gas separation and catalysis. In particular, it is ideal for the catalytic deactivation of nerve agents and shows great promise as a new generic platform for a wide range of applications. Multiple post-synthetic modification protocols have been developed using NU-1000 as the parent material, making it a potentially useful scaffold for several catalytic applications. The procedure for the preparation of NU-1000 can be scaled up reliably, and it is suitablemore » for the production of 50 g of the tetracarboxylic acid containing organic linker and 200 mg–2.5 g of NU-1000. Lastly, the entire synthesis is performed without purification by column chromatography and can be completed within 10 d.« less

  10. Surface chemistry of metal-organic frameworks at the liquid-solid interface.

    PubMed

    Zacher, Denise; Schmid, Rochus; Wöll, Christof; Fischer, Roland A

    2011-01-03

    Metal-organic frameworks (MOFs) are a fascinating class of novel inorganic-organic hybrid materials. They are essentially based on classic coordination chemistry and hold much promise for unique applications ranging from gas storage and separation to chemical sensing, catalysis, and drug release. The evolution of the full innovative potential of MOFs, in particular for nanotechnology and device integration, however requires a fundamental understanding of the formation process of MOFs. Also necessary is the ability to control the growth of thin MOF films and the positioning of size- and shape-selected crystals as well as MOF heterostructures on a given surface in a well-defined and oriented fashion. MOFs are solid-state materials typically formed by solvothermal reactions and their crystallization from the liquid phase involves the surface chemistry of their building blocks. This Review brings together various key aspects of the surface chemistry of MOFs.

  11. Understanding the kinetics of adsorption in narrow channel metal organic frameworks

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Simmons, Jason; Yildirim, Taner

    2010-03-01

    Advancements in the controlled synthesis of metal organic frameworks (MOFs) have lead to impressive increases in hydrogen storage capacities and enhanced binding energies that may offer higher temperature operation. Given that the optimum pore size for hydrogen adsorption is on the order of 7 Angstroms, diffusion of hydrogen into these materials can play an important role in their ultimate implementation. In this presentation we use a combination of experimental and computational techniques, including gas sorption and neutron scattering measurements and detailed first-principles calculations, to better understand the kinetic limitations to adsorption in narrow channel MOF. In particular we show that the adsorption is diffusion limited with a significant activation barrier of ˜70 meV, and that this barrier is phonon-mediated. This work demonstrates the importance of considering kinetic effects in addition to pore volume and heats of adsorption when optimizing MOF materials for hydrogen storage.

  12. The role of metal-organic frameworks in a carbon-neutral energy cycle

    NASA Astrophysics Data System (ADS)

    Schoedel, Alexander; Ji, Zhe; Yaghi, Omar M.

    2016-04-01

    Reducing society's reliance on fossil fuels presents one of the most pressing energy and environmental challenges facing our planet. Hydrogen, methane and carbon dioxide, which are some of the smallest and simplest molecules known, may lie at the centre of solving this problem through realization of a carbon-neutral energy cycle. Potentially, this could be achieved through the deployment of hydrogen as the fuel of the long term, methane as a transitional fuel, and carbon dioxide capture and sequestration as the urgent response to ongoing climate change. Here we detail strategies and technologies developed to overcome the difficulties encountered in the capture, storage, delivery and conversion of these gas molecules. In particular, we focus on metal-organic frameworks in which metal oxide ‘hubs’ are linked with organic ‘struts’ to make materials of ultrahigh porosity, which provide a basis for addressing this challenge through materials design on the molecular level.

  13. Scalable synthesis and post-modification of a mesoporous metal-organic framework called NU-1000

    SciTech Connect

    Wang, Timothy C.; Vermeulen, Nicolaas A.; Kim, In Soo; Martinson, Alex B. F.; Stoddart, J. Fraser; Hupp, Joseph T.; Farha, Omar K.

    2015-12-17

    The synthesis of NU-1000, a mesoporous metal-organic framework (MOF), can be conducted efficiently on a multigram scale from inexpensive starting materials. NU-1000 has been reported as an excellent candidate for gas separation and catalysis. In particular, it is ideal for the catalytic deactivation of nerve agents and shows great promise as a new generic platform for a wide range of applications. Multiple post-synthetic modification protocols have been developed using NU-1000 as the parent material, making it a potentially useful scaffold for several catalytic applications. The procedure for the preparation of NU-1000 can be scaled up reliably, and it is suitable for the production of 50 g of the tetracarboxylic acid containing organic linker and 200 mg–2.5 g of NU-1000. Lastly, the entire synthesis is performed without purification by column chromatography and can be completed within 10 d.

  14. Structural and dynamic studies of substrate binding in porous metal-organic frameworks.

    PubMed

    Easun, Timothy L; Moreau, Florian; Yan, Yong; Yang, Sihai; Schröder, Martin

    2017-01-03

    Porous metal-organic frameworks (MOFs) are the subject of considerable research interest because of their high porosity and capability of specific binding to small molecules, thus underpinning a wide range of materials functions such as gas adsorption, separation, drug delivery, catalysis, and sensing. MOFs, constructed by the designed assembly of metal ions and functional organic linkers, are an emerging class of porous materials with extended porous structures containing periodic binding sites. MOFs thus provide a new platform for the study of the chemistry and reactivity of small molecules in confined pores using advanced diffraction and spectroscopic techniques. In this review, we focus on recent progress in experimental investigations on the crystallographic, dynamic and kinetic aspects of substrate binding within porous MOFs. In particular, we focus on studies on host-guest interactions involving open metal sites or pendant functional groups in the pore as the primary binding sites for guest molecules.

  15. Hybrid crystals comprising metal-organic frameworks and functional particles: synthesis and applications.

    PubMed

    Li, Shaozhou; Huo, Fengwei

    2014-11-12

    Hybrid crystals containing encapsulated functional species exhibit promising novel physical and chemical properties. The realization of many properties critically depends on the selection of suitable functional species for incorporation, the rational control of the crystallinity of the host materials, and the manipulation of the distribution of the encapsulated species; only a few hybrid crystals achieve this. Here, a novel synthetic method enables the encapsulation of functional species within crystalline metal-organic frameworks (MOFs). Various kinds of single-crystalline MOFs with incorporated particles are presented. The encapsulated particles can be distributed in a controllable manner, and the hybrid crystals are applied to the heterogeneous catalysis of the reduction of nitroarenes. These findings suggest a general approach for the construction of MOF materials with potential applications; by combining species and MOFs with suitable functionalities, new properties--not possible by other means--may arise.

  16. Nanoscale zinc-based metal-organic framework with high capacity for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Shi, Changdong; Gao, Yuanrui; Liu, Lili; Song, Yidan; Wang, Xianmei; Liu, Hong-Jiang; Liu, Qi

    2016-12-01

    Layered zinc-based metal-organic framework ([Zn(4,4'-bpy)(tfbdc)(H2O)2], Zn-LMOF) nanosheets were synthesized by a facile hydrothermal method (4,4'-bpy = 4,4'-bipyridine, H2tfbdc = tetrafluoroterephthalic acid). The materials were characterized by IR spectrum, elemental analysis, thermogravimetric analysis, powder X-ray diffraction, transmission electron microscope (TEM), scanning electron microscope (SEM), and the Brunauer-Emmett-Teller (BET) surface. When the Zn-LMOF nanosheets with the thickness of about 24 ± 8 nm were used as an anode material of lithium-ion batteries, not only the Zn-LMOF electrode shows a high reversible capacity, retaining 623 mAh g-1 after 100 cycles at a current density of 50 mA g-1 but also exhibits an excellent cyclic stability and a higher rate performance.

  17. Transferable Force Field for Metal-Organic Frameworks from First-Principles: BTW-FF.

    PubMed

    Bristow, Jessica K; Tiana, Davide; Walsh, Aron

    2014-10-14

    We present an ab-initio derived force field to describe the structural and mechanical properties of metal-organic frameworks (or coordination polymers). The aim is a transferable interatomic potential that can be applied to MOFs regardless of metal or ligand identity. The initial parametrization set includes MOF-5, IRMOF-10, IRMOF-14, UiO-66, UiO-67, and HKUST-1. The force field describes the periodic crystal and considers effective atomic charges based on topological analysis of the Bloch states of the extended materials. Transferable potentials were developed for the four organic ligands comprising the test set and for the associated Cu, Zn, and Zr metal nodes. The predicted materials properties, including bulk moduli and vibrational frequencies, are in agreement with explicit density functional theory calculations. The modal heat capacity and lattice thermal expansion are also predicted.

  18. Adsorption of silver nanoparticles from aqueous solution on copper-based metal organic frameworks (HKUST-1).

    PubMed

    Conde-González, J E; Peña-Méndez, E M; Rybáková, S; Pasán, J; Ruiz-Pérez, C; Havel, J

    2016-05-01

    Silver nanoparticles (AgNP) are emerging pollutants. The use of novel materials such as Cu-(benzene 1,3,5-tricarboxylate, BTC) Metal-Organic Framework (MOFs), for AgNP adsorption and their removal from aqueous solutions has been studied. The effect of different parameters was followed and isotherm model was suggested. MOFs adsorbed fast and efficiently AgNP in the range C0 < 10 mg L(-1), being Freundlich isotherm (R = 0.993) these data fitted to. Among studied parameters a remarkable effect of chloride on sorption was found, thus their possible interactions were considered. The high adsorption efficiency of AgNP was achieved and it was found to be very fast. The feasibility of adsorption on Cu-(BTC) was proved in spiked waters. The results showed the potential interest of new material as adsorbent for removing AgNP from environment.

  19. A scalable synthesis of a mesoporous metal-organic framework called NU-1000.

    SciTech Connect

    Wang, Timothy C.; Vermeulen, Nicolaas A.; Kim, In Soo; Martinson, Alex B. F.; Stoddart, J. Fraser; Hupp, Joseph T.; Farha, Omar K.

    2016-01-01

    The synthesis of NU-1000, a mesoporous metal-organic framework (MOF), can be conducted efficiently on a multigram scale from inexpensive starting materials. NU-1000 has been reported as an excellent candidate for gas separation and catalysis. In particular, it is ideal for the catalytic deactivation of nerve agents and shows great promise as a new generic platform for a wide range of applications. Multiple post-synthetic modification protocols have been developed using NU-1000 as the parent material, making it a potentially useful scaffold for several catalytic applications. The procedure for the preparation of NU-1000 can be scaled up reliably and is suitable for the production of 50 grams of the requisite organic linker and ?? grams of NU-1000. The entire synthesis is performed without purification by column chromatography and can be completed within 10 days.

  20. Fluorous Metal Organic Frameworks as Superhydrophobic Adsorbents for Oil Spill Cleanup and Hydrocarbons Storage

    SciTech Connect

    Yang, Chi; Mather, Qian; Wang, Xiaoping; Kaipa, Ushasree; Nesterov, Vladimir; Venero, Augustin; Omary, Mohammad A

    2011-01-01

    We demonstrate that fluorous metal-organic frameworks (FMOFs) are highly hydrophobic porous materials with a high capacity and affinity to C{sub 6}-C{sub 8} hydrocarbons of oil components. FMOF-1 exhibits reversible adsorption with a high capacity for n-hexane, cyclohexane, benzene, toluene, and p-xylene, with no detectable water adsorption even at near 100% relative humidity, drastically outperforming activated carbon and zeolite porous materials. FMOF-2, obtained from annealing FMOF-1, shows enlarged cages and channels with double toluene adsorption vs FMOF-1 based on crystal structures. The results suggest great promise for FMOFs in applications such as removal of organic pollutants from oil spills or ambient humid air, hydrocarbon storage and transportation, water purification, etc. under practical working conditions.

  1. Molecular simulation of adsorption and diffusion of hydrogen in metal-organic frameworks.

    PubMed

    Yang, Qingyuan; Zhong, Chongli

    2005-06-23

    Metal-organic frameworks (MOFs) are thought to be a set of promising hydrogen storage materials; however, little is known about the interactions between hydrogen molecules and pore walls as well as the diffusivities of hydrogen in MOFs. In this work, we performed a systematic molecular simulation study on the adsorption and diffusion of hydrogen in MOFs to provide insight into molecular-level details of the underlying mechanisms. This work shows that metal-oxygen clusters are preferential adsorption sites for hydrogen in MOFs, and the effect of the organic linkers becomes evident with increasing pressure. The hydrogen storage capacity of MOFs is similar to carbon nanotubes, which is higher than zeolites. Diffusion of hydrogen in MOFs is an activated process that is similar to diffusion in zeolites. The information derived in this work is useful to guide the future rational design and synthesis of tailored MOF materials with improved hydrogen adsorption capability.

  2. Copper benzene tricarboxylate metal-organic framework with wide permanent mesopores stabilized by Keggin polyoxometallate ions.

    PubMed

    Wee, Lik H; Wiktor, Christian; Turner, Stuart; Vanderlinden, Willem; Janssens, Nikki; Bajpe, Sneha R; Houthoofd, Kristof; Van Tendeloo, Gustaaf; De Feyter, Steven; Kirschhock, Christine E A; Martens, Johan A

    2012-07-04

    Porous solids with organized multiple porosity are of scientific and technological importance for broadening the application range from traditional areas of catalysis and adsorption/separation to drug release and biomedical imaging. Synthesis of crystalline porous materials offering a network of uniform micro- and mesopores remains a major scientific challenge. One strategy is based on variation of synthesis parameters of microporous networks, such as, for example, zeolites or metal-organic frameworks (MOFs). Here, we show the rational development of an hierarchical variant of the microporous cubic Cu(3)(BTC)(2) (BTC = 1,3,5-benzenetricarboxylate) HKUST-1 MOF having strictly repetitive 5 nm wide mesopores separated by uniform microporous walls in a single crystal structure. This new material coined COK-15 (COK = Centrum voor Oppervlaktechemie en Katalyse) was synthesized via a dual-templating approach. Stability was enhanced by Keggin type phosphotungstate (HPW) systematically occluded in the cavities constituting the walls between the mesopores.

  3. Recent Progress in Metal-Organic Frameworks and Their Derived Nanostructures for Energy and Environmental Applications.

    PubMed

    Xie, Zhiqiang; Xu, Wangwang; Cui, Xiaodan; Wang, Ying

    2017-04-22

    Metal-organic frameworks (MOFs), as a very promising category of porous materials, have attracted increasing interest from research communities due to their extremely high surface areas, diverse nanostructures, and unique properties. In recent years, there is a growing body of evidence to indicate that MOFs can function as ideal templates to prepare various nanostructured materials for energy and environmental cleaning applications. Recent progress in the design and synthesis of MOFs and MOF-derived nanomaterials for particular applications in lithium-ion batteries, sodium-ion batteries, supercapacitors, dye-sensitized solar cells, and heavy-metal-ion detection and removal is reviewed herein. In addition, the remaining major challenges in the above fields are discussed and some perspectives for future research efforts in the development of MOFs are also provided. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Enhanced Cooperativity in Supported Spin-Crossover Metal-Organic Frameworks.

    PubMed

    Groizard, Thomas; Papior, Nick; Le Guennic, Boris; Robert, Vincent; Kepenekian, Mikaël

    2017-07-20

    The impact of surface deposition on cooperativity is explored in Au(111)-supported self-assembled metal-organic frameworks (MOFs) based on Fe(II) ions. Using a thermodynamic model, we first demonstrate that dimensionality reduction combined with deposition on a metal surface is likely to deeply enhance the spin-crossover cooperativity, going from γ3D = 16 K for the bulk material to γ2D(supp) = 386 K for its 2D supported derivative. On the basis of density functional theory, we then elucidate the electronic structure of a promising Fe-based MOF. A chemical strategy is proposed to turn a weakly interacting magnetic system into a strongly cooperative spin-crossover monolayer with γMOF(Au(111)) = 83 K. These results open a promising route to the fabrication of cooperative materials based on SCO Fe(II) platforms.

  5. Efficient photocatalytic degradation of rhodamine 6G with a quantum dot-metal organic framework nanocomposite.

    PubMed

    Kaur, Rajnish; Vellingiri, Kowsalya; Kim, Ki-Hyun; Paul, A K; Deep, Akash

    2016-07-01

    The hybrid structures of metal organic frameworks (MOFs) and nanoparticles may offer the realization of effective photocatalytic materials due to combined benefits of the porous and molecular sieving properties of MOF matrix and the functional characteristics of encapsulated nanoparticles. In this study, cadmium telluride (CdTe) quantum dots (QD) are conjugated with a europium-MOF for the synthesis of a novel nanocomposite material with photocatalytic properties. Successful synthesis of a QD/Eu-MOF nanocomposite was characterized with various spectroscopic and microscopic techniques. This QD/Eu-MOF is found to be an effective catalyst to complete the degradation of Rhodamine 6G dye within 50 min. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. System and method for generating and/or screening potential metal-organic frameworks

    DOEpatents

    Wilmer, Christopher E; Leaf, Michael; Snurr, Randall Q; Farha, Omar K; Hupp, Joseph T

    2014-12-02

    A system and method for systematically generating potential metal-organic framework (MOFs) structures given an input library of building blocks is provided herein. One or more material properties of the potential MOFs are evaluated using computational simulations. A range of material properties (surface area, pore volume, pore size distribution, powder x-ray diffraction pattern, methane adsorption capability, and the like) can be estimated, and in doing so, illuminate unidentified structure-property relationships that may only have been recognized by taking a global view of MOF structures. In addition to identifying structure-property relationships, this systematic approach to identify the MOFs of interest is used to identify one or more MOFs that may be useful for high pressure methane storage.

  7. System and method for generating and/or screening potential metal-organic frameworks

    DOEpatents

    Wilmer, Christopher E; Leaf, Michael; Snurr, Randall Q; Farha, Omar K; Hupp, Joseph T

    2015-04-21

    A system and method for systematically generating potential metal-organic framework (MOFs) structures given an input library of building blocks is provided herein. One or more material properties of the potential MOFs are evaluated using computational simulations. A range of material properties (surface area, pore volume, pore size distribution, powder x-ray diffraction pattern, methane adsorption capability, and the like) can be estimated, and in doing so, illuminate unidentified structure-property relationships that may only have been recognized by taking a global view of MOF structures. In addition to identifying structure-property relationships, this systematic approach to identify the MOFs of interest is used to identify one or more MOFs that may be useful for high pressure methane storage.

  8. Multi-walled carbon nanotubes and metal-organic framework nanocomposites as novel hybrid electrode materials for the determination of nano-molar levels of lead in a lab-on-valve format.

    PubMed

    Wang, Yang; Wu, Yichun; Xie, Jing; Ge, Huali; Hu, Xiaoya

    2013-09-07

    Metal-organic frameworks have been the subject of intense research because of their unique physicochemical properties. The presented study investigates the application of multi-wall carbon nanotubes and metal-organic frameworks (MWCNTs@Cu3(BTC)2) nanoparticles-modified electrode for the determination of trace levels of lead. The nanocomposites were prepared by solvothermal synthesis and characterized in detail. The experimental procedure was carried out by accumulating lead on the electrode surface and subsequently measuring with differential pulse anodic stripping voltammetry in a lab-on-valve format. The main parameters affecting the analytical performance, including the amount of MWCNTs@Cu3(BTC)2 suspension, supporting electrolyte and its pH, stripping mode, and flow rate, have been investigated in detail. Under the optimum conditions, the oxidation peak current displayed a calibration response for lead over a concentration range from 1.0 × 10(-9) to 5.0 × 10(-8) mol L(-1) with a excellent detection limit of 7.9 × 10(-10) mol L(-1). The relative standard deviation of 7 successive scans was 3.10% for 1.0 × 10(-8) mol L(-1) lead. The established method showed a great improvement in sensitivity and sample throughput for lead analysis.

  9. Research Update: Mechanical properties of metal-organic frameworks - Influence of structure and chemical bonding

    NASA Astrophysics Data System (ADS)

    Li, Wei; Henke, Sebastian; Cheetham, Anthony K.

    2014-12-01

    Metal-organic frameworks (MOFs), a young family of functional materials, have been attracting considerable attention from the chemistry, materials science, and physics communities. In the light of their potential applications in industry and technology, the fundamental mechanical properties of MOFs, which are of critical importance for manufacturing, processing, and performance, need to be addressed and understood. It has been widely accepted that the framework topology, which describes the overall connectivity pattern of the MOF building units, is of vital importance for the mechanical properties. However, recent advances in the area of MOF mechanics reveal that chemistry plays a major role as well. From the viewpoint of materials science, a deep understanding of the influence of chemical effects on MOF mechanics is not only highly desirable for the development of novel functional materials with targeted mechanical response, but also for a better understanding of important properties such as structural flexibility and framework breathing. The present work discusses the intrinsic connection between chemical effects and the mechanical behavior of MOFs through a number of prototypical examples.

  10. Predictive framework for shape-selective separations in three-dimensional zeolites and metal-organic frameworks.

    PubMed

    First, Eric L; Gounaris, Chrysanthos E; Floudas, Christodoulos A

    2013-05-07

    With the growing number of zeolites and metal-organic frameworks (MOFs) available, computational methods are needed to screen databases of structures to identify those most suitable for applications of interest. We have developed novel methods based on mathematical optimization to predict the shape selectivity of zeolites and MOFs in three dimensions by considering the energy costs of transport through possible pathways. Our approach is applied to databases of over 1800 microporous materials including zeolites, MOFs, zeolitic imidazolate frameworks, and hypothetical MOFs. New materials are identified for applications in gas separations (CO2/N2, CO2/CH4, and CO2/H2), air separation (O2/N2), and chemicals (propane/propylene, ethane/ethylene, styrene/ethylbenzene, and xylenes).

  11. Postsynthetic Modification of an Alkyne-Tagged Zirconium Metal-Organic Framework via a "Click" Reaction.

    PubMed

    Li, Bijian; Gui, Bo; Hu, Guiping; Yuan, Daqiang; Wang, Cheng

    2015-06-01

    Herein, we report the synthesis and postsynthetic modification of a novel alkyne-tagged zirconium metal-organic framework, UiO-68-alkyne. The alkynyl groups in the pore surface were subjected to a "click" reaction, achieving quantitative conversion and maintaining the crystallinity of the framework.

  12. Luminescent metal-organic framework films as highly sensitive and fast-response oxygen sensors.

    PubMed

    Dou, Zhongshang; Yu, Jiancan; Cui, Yuanjing; Yang, Yu; Wang, Zhiyu; Yang, Deren; Qian, Guodong

    2014-04-16

    Luminescent metal-organic framework films, CPM-5⊃Tb(3+) and MIL-100(In)⊃Tb(3+), have been constructed by postfunctionalization of two porous indium-organic frameworks with different structures, respectively. The MIL-100(In)⊃Tb(3+) film shows high oxygen sensitivity (KSV = 7.59) and short response/recovery time (6 s/53 s).

  13. Foldable interpenetrated metal-organic frameworks/carbon nanotubes thin film for lithium–sulfur batteries

    PubMed Central

    Mao, Yiyin; Li, Gaoran; Guo, Yi; Li, Zhoupeng; Liang, Chengdu; Peng, Xinsheng; Lin, Zhan

    2017-01-01

    Lithium–sulfur batteries are promising technologies for powering flexible devices due to their high energy density, low cost and environmental friendliness, when the insulating nature, shuttle effect and volume expansion of sulfur electrodes are well addressed. Here, we report a strategy of using foldable interpenetrated metal-organic frameworks/carbon nanotubes thin film for binder-free advanced lithium–sulfur batteries through a facile confinement conversion. The carbon nanotubes interpenetrate through the metal-organic frameworks crystal and interweave the electrode into a stratified structure to provide both conductivity and structural integrity, while the highly porous metal-organic frameworks endow the electrode with strong sulfur confinement to achieve good cyclability. These hierarchical porous interpenetrated three-dimensional conductive networks with well confined S8 lead to high sulfur loading and utilization, as well as high volumetric energy density. PMID:28262801

  14. Foldable interpenetrated metal-organic frameworks/carbon nanotubes thin film for lithium-sulfur batteries.

    PubMed

    Mao, Yiyin; Li, Gaoran; Guo, Yi; Li, Zhoupeng; Liang, Chengdu; Peng, Xinsheng; Lin, Zhan

    2017-03-06

    Lithium-sulfur batteries are promising technologies for powering flexible devices due to their high energy density, low cost and environmental friendliness, when the insulating nature, shuttle effect and volume expansion of sulfur electrodes are well addressed. Here, we report a strategy of using foldable interpenetrated metal-organic frameworks/carbon nanotubes thin film for binder-free advanced lithium-sulfur batteries through a facile confinement conversion. The carbon nanotubes interpenetrate through the metal-organic frameworks crystal and interweave the electrode into a stratified structure to provide both conductivity and structural integrity, while the highly porous metal-organic frameworks endow the electrode with strong sulfur confinement to achieve good cyclability. These hierarchical porous interpenetrated three-dimensional conductive networks with well confined S8 lead to high sulfur loading and utilization, as well as high volumetric energy density.

  15. Foldable interpenetrated metal-organic frameworks/carbon nanotubes thin film for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Mao, Yiyin; Li, Gaoran; Guo, Yi; Li, Zhoupeng; Liang, Chengdu; Peng, Xinsheng; Lin, Zhan

    2017-03-01

    Lithium-sulfur batteries are promising technologies for powering flexible devices due to their high energy density, low cost and environmental friendliness, when the insulating nature, shuttle effect and volume expansion of sulfur electrodes are well addressed. Here, we report a strategy of using foldable interpenetrated metal-organic frameworks/carbon nanotubes thin film for binder-free advanced lithium-sulfur batteries through a facile confinement conversion. The carbon nanotubes interpenetrate through the metal-organic frameworks crystal and interweave the electrode into a stratified structure to provide both conductivity and structural integrity, while the highly porous metal-organic frameworks endow the electrode with strong sulfur confinement to achieve good cyclability. These hierarchical porous interpenetrated three-dimensional conductive networks with well confined S8 lead to high sulfur loading and utilization, as well as high volumetric energy density.

  16. Effect of organic substituents on the adsorption of carbon dioxide on a metal-organic framework

    NASA Astrophysics Data System (ADS)

    Thu Ha, Nguyen Thi; Lefedova, O. V.; Ha, Nguyen Ngoc

    2017-01-01

    The adsorption of carbon dioxide on the MOF-5 metal-organic framework and modifications of it obtained by replacing the hydrogen atoms in the organic ligands with electron donor (-CH3,-OCH3) or electron acceptor groups (-CN,-NO2) is investigated using the grand canonical Monte Carlo (GCMC) method and density functional theory (DFT). It is shown that the adsorption of carbon dioxide molecules on the structures of metal-organic frameworks is most likely on Zn4O clusters, and that the adsorption of carbon dioxide is of a physical nature. The presence of substituents-CH3,-OCH3,-CN in metal-organic frameworks increases their capacity to adsorb carbon dioxide, while that of nitro groups (-NO2) has the opposite effect.

  17. Structural Effects in Visible-Light-Responsive Metal-Organic Frameworks Incorporating ortho-Fluoroazobenzenes.

    PubMed

    Castellanos, Sonia; Goulet-Hanssens, Alexis; Zhao, Fangli; Dikhtiarenko, Alla; Pustovarenko, Alexey; Hecht, Stefan; Gascon, Jorge; Kapteijn, Freek; Bléger, David

    2016-01-11

    The ability to control the interplay of materials with low-energy photons is important as visible light offers several appealing features compared to ultraviolet radiation (less damaging, more selective, predominant in the solar spectrum, possibility to increase the penetration depth). Two different metal-organic frameworks (MOFs) were synthesized from the same linker bearing all-visible ortho-fluoroazobenzene photoswitches as pendant groups. The MOFs exhibit different architectures that strongly influence the ability of the azobenzenes to isomerize inside the voids. The framework built with Al-based nodes has congested 1D channels that preclude efficient isomerization. As a result, local light-heat conversion can be used to alter the CO2 adsorption capacity of the material on exposure to green light. The second framework, built with Zr nodes, provides enough room for the photoswitches to isomerize, which leads to a unique bistable photochromic MOF that readily responds to blue and green light. The superiority of green over UV irradiation was additionally demonstrated by reflectance spectroscopy and analysis of digested samples. This material offers promising perspectives for liquid-phase applications such as light-controlled catalysis and adsorptive separation.

  18. Experimental comparison of chiral metal-organic framework used as stationary phase in chromatography.

    PubMed

    Xie, Sheng-Ming; Zhang, Mei; Fei, Zhi-Xin; Yuan, Li-Ming

    2014-10-10

    Chiral metal-organic frameworks (MOFs) are a new class of multifunctional material, which possess diverse structures and unusual properties such as high surface area, uniform and permanent cavities, as well as good chemical and thermal stability. Their chiral functionality makes them attractive as novel enantioselective adsorbents and stationary phases in separation science. In this paper, the experimental comparison of a chiral MOF [In₃O(obb)₃(HCO₂)(H₂O)] solvent used as a stationary phase was investigated in gas chromatography (GC), high-performance liquid chromatography (HPLC) and capillary electrochromatography (CEC). The potential relationship between the structure and components of chiral MOFs with their chiral recognition ability and selectivity are presented. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. High-pressure, ambient temperature hydrogen storage in metal-organic frameworks and porous carbon

    NASA Astrophysics Data System (ADS)

    Beckner, Matthew; Dailly, Anne

    2014-03-01

    We investigated hydrogen storage in micro-porous adsorbents at ambient temperature and pressures up to 320 bar. We measured three benchmark adsorbents: two metal-organic frameworks, Cu3(1,3,5-benzenetricarboxylate)2 [Cu3(btc)2; HKUST-1] and Zn4O(1,3,5-benzenetribenzoate)2 [Zn4O(btb)2; MOF-177], and the activated carbon MSC-30. In this talk, we focus on adsorption enthalpy calculations using a single adsorption isotherm. We use the differential form of the Claussius-Clapeyron equation applied to the Dubinin-Astakhov adsorption model to calculate adsorption enthalpies. Calculation of the adsorption enthalpy in this way gives a temperature independent enthalpy of 5-7 kJ/mol at the lowest coverage for the three materials investigated. Additionally, we discuss the assumptions and corrections that must be made when calculating adsorption isotherms at high-pressure and adsorption enthalpies.

  20. Modulation by Amino Acids: Toward Superior Control in the Synthesis of Zirconium Metal-Organic Frameworks.

    PubMed

    Gutov, Oleksii V; Molina, Sonia; Escudero-Adán, Eduardo C; Shafir, Alexandr

    2016-09-12

    The synthesis of zirconium metal-organic frameworks (Zr MOFs) modulated by various amino acids, including l-proline, glycine, and l-phenylalanine, is shown to be a straightforward approach toward functional-group incorporation and particle-size control. High yields in Zr-MOF synthesis are achieved by employing 5 equivalents of the modulator at 120 °C. At lower temperatures, the method provides a series of Zr MOFs with increased particle size, including many suitable for single-crystal X-ray diffraction studies. Furthermore, amino acid modulators can be incorporated at defect sites in Zr MOFs with an amino acid/ligand ratio of up to 1:1, depending on the ligand structure and reaction conditions. The MOFs obtained through amino acid modulation exhibit an improved CO2 -capture capacity relative to nonfunctionalized materials.

  1. Dual-Functional Electrocatalyst Derived from Iron-Porphyrin-Encapsulated Metal-Organic Frameworks.

    PubMed

    Park, Jungwon; Lee, Hyunjoon; Bae, Young Eun; Park, Kyoung Chul; Ji, Hoon; Jeong, Nak Cheon; Lee, Min Hyung; Kwon, Oh Joong; Lee, Chang Yeon

    2017-08-30

    Active, stable electrocatalysts based on non-precious metals for the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) are critical for the development of cost-effective, efficient renewable energy technologies. Here, Fe/Fe3C-embedded nitrogen-doped carbon was fabricated via pyrolysis of iron-porphyrin-encapsulated mesoporous metal-organic frameworks [PCN-333 (Fe), where "PCN" stands for "porous coordination network"] at 700 °C. The various characterization techniques confirmed that Fe- and Fe3C-containing Fe-N-C material (FeP-P333-700) was successfully prepared by pyrolysis of porphyrin-encapsulated PCN-333 (Fe). FeP-P333-700 exhibited superior electrocatalytic performance for the ORR and HER owing to the synergistic effect of Fe/Fe3C and Fe-N-C active sites.

  2. Nanoporous designer solids with huge lattice constant gradients: multiheteroepitaxy of metal-organic frameworks.

    PubMed

    Wang, Zhengbang; Liu, Jinxuan; Lukose, Binit; Gu, Zhigang; Weidler, Peter G; Gliemann, Hartmut; Heine, Thomas; Wöll, Christof

    2014-03-12

    We demonstrate the realization of hierarchically organized MOF (metal-organic framework) multilayer systems with pronounced differences in the size of the nanoscale pores. Unusually large values for the lattice constant mismatch at the MOF-MOF heterojunctions are made possible by a particular liquid-phase epitaxy process. The multiheteroepitaxy is demonstrated for the isoreticular SURMOF-2 series [ Liu et al. Sci. Rep. 2012 , 2 , 921 ] by fabricating trilayer systems with lattice constants of 1.12, 1.34, and 1.55 nm. Despite these large (20%) lattice mismatches, highly crystalline, oriented multilayers were obtained. A thorough theoretical analysis of the MOF-on-MOF heterojunction structure and energetics allows us to identify the two main reasons for this unexpected tolerance of large lattice mismatch: the healing of vacancies with acetate groups and the low elastic constant of MOF materials.

  3. Gas storage in porous metal-organic frameworks for clean energy applications.

    PubMed

    Ma, Shengqian; Zhou, Hong-Cai

    2010-01-07

    Depletion of fossil oil deposits and the escalating threat of global warming have put clean energy research, which includes the search for clean energy carriers such as hydrogen and methane as well as the reduction of carbon dioxide emissions, on the urgent agenda. A significant technical challenge has been recognized as the development of a viable method to efficiently trap hydrogen, methane and carbon dioxide gas molecules in a confined space for various applications. This issue can be addressed by employing highly porous materials as storage media, and porous metal-organic frameworks (MOFs) which have exceptionally high surface areas as well as chemically-tunable structures are playing an unusual role in this respect. In this feature article we provide an overview of the current status of clean energy applications of porous MOFs, including hydrogen storage, methane storage and carbon dioxide capture.

  4. Iron-Based Metal-Organic Frameworks as Catalysts for Visible Light-Driven Water Oxidation.

    PubMed

    Chi, Le; Xu, Qian; Liang, Xiaoyu; Wang, Jide; Su, Xintai

    2016-03-09

    The development of earth-abundant, active, and stable catalysts is important for solar energy conversion. Metal-organic frameworks (MOFs) have been viewed as a promising class of porous materials, which may have innovative application in photocatalysis. In this paper, three types of Fe-based MOFs and their aminofunctionalized derivatives have been fabricated and systematically studied as water oxidation catalysts (WOCs) for oxygen evolution under visible light irradiation. MIL-101(Fe) possesses a higher current density and earlier onset potential and exhibits excellent visible light-driven oxygen evolution activity than the other Fe-based catalysts. It speeds up the oxygen evolution reaction rate with the higher initial turnover frequencies value of 0.10 s(-1). Our study demonstrates that Fe-based MOFs as efficient WOCs are promising candidates for photocatalytic water oxidation process. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Competitive Coordination Strategy to Finely Tune Pore Environment of Zirconium-Based Metal-Organic Frameworks.

    PubMed

    He, Ting; Ni, Bing; Xu, Xiaobin; Li, Haoyi; Lin, Haifeng; Yuan, Wenjuan; Luo, Jun; Hu, Wenping; Wang, Xun

    2017-07-12

    Metal-organic frameworks (MOFs) are a class of crystalline porous materials with reticular architectures. Precisely tuning pore environment of MOFs has drawn tremendous attention but remains a great challenge. In this work, we demonstrate a competitive coordination approach to synthesize a series of zirconium-metalloporphyrinic MOFs through introducing H2O and monocarboxylic acid as modulating reagents, in which well-ordered mesoporous channels could be observed clearly under conventional transmission electron microscopy. Owing to plenty of unsaturated Lewis acid catalytic sites exposed in the visualized mesoporous channels, these structures exhibit outstanding catalytic activity and excellent stability in the chemical fixation of carbon dioxide to cyclic carbonates. The zirconium-based MOFs with ordered channel structures are expected to pave the way to expand the potential applications of MOFs.

  6. Condensation of Methane in the Metal-Organic Framework IRMOF-1: Evidence for Two Critical Points.

    PubMed

    Höft, Nicolas; Horbach, Jürgen

    2015-08-19

    Extensive grand canonical Monte Carlo simulations in combination with successive umbrella sampling are used to investigate the condensation of methane in the nanoporous crystalline material IRMOF-1. Two different types of novel condensation transitions are found, each of them ending in a critical point: (i) a fluid-fluid transition at higher densities (the analog of the liquid-gas transition in the bulk) and (ii) a phase transition at low densities on the surface of the IRMOF-1 structure. The nature of these transitions is different from the usual capillary condensation in thin films and cylindrical pores where the coexisting phases are confined in one or two of the three spatial dimensions. In contrast to that, in IRMOF-1 the different phases can be described as bulk phases that are inhomogeneous due to the presence of the metal-organic framework. As a consequence, the condensation transitions in IRMOF-1 belong to the three-dimensional (3D) Ising universality class.

  7. Construction of hierarchically porous metal-organic frameworks through linker labilization

    NASA Astrophysics Data System (ADS)

    Yuan, Shuai; Zou, Lanfang; Qin, Jun-Sheng; Li, Jialuo; Huang, Lan; Feng, Liang; Wang, Xuan; Bosch, Mathieu; Alsalme, Ali; Cagin, Tahir; Zhou, Hong-Cai

    2017-05-01

    A major goal of metal-organic framework (MOF) research is the expansion of pore size and volume. Although many approaches have been attempted to increase the pore size of MOF materials, it is still a challenge to construct MOFs with precisely customized pore apertures for specific applications. Herein, we present a new method, namely linker labilization, to increase the MOF porosity and pore size, giving rise to hierarchical-pore architectures. Microporous MOFs with robust metal nodes and pro-labile linkers were initially synthesized. The mesopores were subsequently created as crystal defects through the splitting of a pro-labile-linker and the removal of the linker fragments by acid treatment. We demonstrate that linker labilization method can create controllable hierarchical porous structures in stable MOFs, which facilitates the diffusion and adsorption process of guest molecules to improve the performances of MOFs in adsorption and catalysis.

  8. Cu₃(hexaiminotriphenylene)₂: an electrically conductive 2D metal-organic framework for chemiresistive sensing.

    PubMed

    Campbell, Michael G; Sheberla, Dennis; Liu, Sophie F; Swager, Timothy M; Dincă, Mircea

    2015-03-27

    The utility of metal-organic frameworks (MOFs) as functional materials in electronic devices has been limited to date by a lack of MOFs that display high electrical conductivity. Here, we report the synthesis of a new electrically conductive 2D MOF, Cu3(HITP)2 (HITP=2,3,6,7,10,11-hexaiminotriphenylene), which displays a bulk conductivity of 0.2 S cm(-1) (pellet, two-point-probe). Devices synthesized by simple drop casting of Cu3(HITP)2 dispersions function as reversible chemiresistive sensors, capable of detecting sub-ppm levels of ammonia vapor. Comparison with the isostructural 2D MOF Ni3(HITP)2 shows that the copper sites are critical for ammonia sensing, indicating that rational design/synthesis can be used to tune the functional properties of conductive MOFs.

  9. Characterization of Adsorption Enthalpy of Novel Water-Stable Zeolites and Metal-Organic Frameworks.

    PubMed

    Kim, Hyunho; Cho, H Jeremy; Narayanan, Shankar; Yang, Sungwoo; Furukawa, Hiroyasu; Schiffres, Scott; Li, Xiansen; Zhang, Yue-Biao; Jiang, Juncong; Yaghi, Omar M; Wang, Evelyn N

    2016-01-22

    Water adsorption is becoming increasingly important for many applications including thermal energy storage, desalination, and water harvesting. To develop such applications, it is essential to understand both adsorbent-adsorbate and adsorbate-adsorbate interactions, and also the energy required for adsorption/desorption processes of porous material-adsorbate systems, such as zeolites and metal-organic frameworks (MOFs). In this study, we present a technique to characterize the enthalpy of adsorption/desorption of zeolites and MOF-801 with water as an adsorbate by conducting desorption experiments with conventional differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). With this method, the enthalpies of adsorption of previously uncharacterized adsorbents were estimated as a function of both uptake and temperature. Our characterizations indicate that the adsorption enthalpies of type I zeolites can increase to greater than twice the latent heat whereas adsorption enthalpies of MOF-801 are nearly constant for a wide range of vapor uptakes.

  10. Characterization of Adsorption Enthalpy of Novel Water-Stable Zeolites and Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Kim, Hyunho; Cho, H. Jeremy; Narayanan, Shankar; Yang, Sungwoo; Furukawa, Hiroyasu; Schiffres, Scott; Li, Xiansen; Zhang, Yue-Biao; Jiang, Juncong; Yaghi, Omar M.; Wang, Evelyn N.

    2016-01-01

    Water adsorption is becoming increasingly important for many applications including thermal energy storage, desalination, and water harvesting. To develop such applications, it is essential to understand both adsorbent-adsorbate and adsorbate-adsorbate interactions, and also the energy required for adsorption/desorption processes of porous material-adsorbate systems, such as zeolites and metal-organic frameworks (MOFs). In this study, we present a technique to characterize the enthalpy of adsorption/desorption of zeolites and MOF-801 with water as an adsorbate by conducting desorption experiments with conventional differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). With this method, the enthalpies of adsorption of previously uncharacterized adsorbents were estimated as a function of both uptake and temperature. Our characterizations indicate that the adsorption enthalpies of type I zeolites can increase to greater than twice the latent heat whereas adsorption enthalpies of MOF-801 are nearly constant for a wide range of vapor uptakes.

  11. Cross coupling between electric and magnetic orders in a multiferroic metal-organic framework

    PubMed Central

    Tian, Ying; Stroppa, Alessandro; Chai, Yisheng; Yan, Liqin; Wang, Shouguo; Barone, Paolo; Picozzi, Silvia; Sun, Young

    2014-01-01

    The coexistence of both electric and magnetic orders in some metal-organic frameworks (MOFs) has yielded a new class of multiferroics beyond inorganic materials. However, the coupling between two orders in multiferroic MOFs has not been convincingly verified yet. Here we present clear experimental evidences of cross coupling between electric and magnetic orders in a multiferroic MOF [(CH3)2NH2]Fe(HCOO)3 with a perovskite structure. The dielelectric constant exhibit a hump just at the magnetic ordering temperature TN. Moreover, both the direct (magnetic field control of dielectric properties) and converse (electric field control of magnetization) magnetoelectric effects have been observed in the multiferroic state. This work opens up new insights on the origin of ferroelectricity in MOFs and highlights their promise as magnetoelectric multiferroics. PMID:25317819

  12. Hydrolytically stable fluorinated metal-organic frameworks for energy-efficient dehydration

    NASA Astrophysics Data System (ADS)

    Cadiau, Amandine; Belmabkhout, Youssef; Adil, Karim; Bhatt, Prashant M.; Pillai, Renjith S.; Shkurenko, Aleksander; Martineau-Corcos, Charlotte; Maurin, Guillaume; Eddaoudi, Mohamed

    2017-05-01

    Natural gas must be dehydrated before it can be transported and used, but conventional drying agents such as activated alumina or inorganic molecular sieves require an energy-intensive desiccant-regeneration step. We report a hydrolytically stable fluorinated metal-organic framework, AlFFIVE-1-Ni (KAUST-8), with a periodic array of open metal coordination sites and fluorine moieties within the contracted square-shaped one-dimensional channel. This material selectively removed water vapor from gas streams containing CO2, N2, CH4, and higher hydrocarbons typical of natural gas, as well as selectively removed both H2O and CO2 in N2-containing streams. The complete desorption of the adsorbed water molecules contained by the AlFFIVE-1-Ni sorbent requires relatively moderate temperature (~105°C) and about half the energy input for commonly used desiccants.

  13. A novel metal-organic framework for high storage and separation of acetylene at room temperature

    NASA Astrophysics Data System (ADS)

    Duan, Xing; Wang, Huizhen; Ji, Zhenguo; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2016-09-01

    A novel 3D microporous metal-organic framework with NbO topology, [Cu2(L)(H2O)2]•(DMF)6·(H2O)2 (ZJU-10, ZJU = Zhejiang University; H4L =2‧-hydroxy-[1,1‧:4‧,1″-terphenyl]-3,3″,5,5″-tetracarboxylic acid; DMF =N,N-dimethylformamide), has been synthesized and structurally characterized. With suitable pore sizes and open Cu2+ sites, ZJU-10a exhibits high BET surface area of 2392 m2/g, as well as moderately high C2H2 volumetric uptake capacity of 132 cm3/cm3. Meanwhile, ZJU-10a is a promising porous material for separation of acetylene from methane and carbon dioxide gas mixtures at room temperature.

  14. Metal-organic framework based mixed matrix membranes: a solution for highly efficient CO2 capture?

    PubMed

    Seoane, Beatriz; Coronas, Joaquin; Gascon, Ignacio; Etxeberria Benavides, Miren; Karvan, Oğuz; Caro, Jürgen; Kapteijn, Freek; Gascon, Jorge

    2015-04-21

    The field of metal-organic framework based mixed matrix membranes (M(4)s) is critically reviewed, with special emphasis on their application in CO2 capture during energy generation. After introducing the most relevant parameters affecting membrane performance, we define targets in terms of selectivity and productivity based on existing literature on process design for pre- and post-combustion CO2 capture. Subsequently, the state of the art in M(4)s is reviewed against these targets. Because final application of these membranes will only be possible if thin separation layers can be produced, the latest advances in the manufacture of M(4) hollow fibers are discussed. Finally, the recent efforts in understanding the separation performance of these complex composite materials and future research directions are outlined.

  15. Computational Design of Metal-Organic Frameworks with High Methane Deliverable Capacity

    NASA Astrophysics Data System (ADS)

    Bao, Yi; Martin, Richard; Simon, Cory; Haranczyk, Maciej; Smit, Berend; Deem, Michael; Deem Team; Haranczyk Team; Smit Team

    Metal-organic frameworks (MOFs) are a rapidly emerging class of nanoporous materials with largely tunable chemistry and diverse applications in gas storage, gas purification, catalysis, etc. Intensive efforts are being made to develop new MOFs with desirable properties both experimentally and computationally in the past decades. To guide experimental synthesis with limited throughput, we develop a computational methodology to explore MOFs with high methane deliverable capacity. This de novo design procedure applies known chemical reactions, considers synthesizability and geometric requirements of organic linkers, and evolves a population of MOFs with desirable property efficiently. We identify about 500 MOFs with higher deliverable capacity than MOF-5 in 10 networks. We also investigate the relationship between deliverable capacity and internal surface area of MOFs. This methodology can be extended to MOFs with multiple types of linkers and multiple SBUs. DE-FG02- 12ER16362.

  16. Characterization of Adsorption Enthalpy of Novel Water-Stable Zeolites and Metal-Organic Frameworks

    PubMed Central

    Kim, Hyunho; Cho, H. Jeremy; Narayanan, Shankar; Yang, Sungwoo; Furukawa, Hiroyasu; Schiffres, Scott; Li, Xiansen; Zhang, Yue-Biao; Jiang, Juncong; Yaghi, Omar M.; Wang, Evelyn N.

    2016-01-01

    Water adsorption is becoming increasingly important for many applications including thermal energy storage, desalination, and water harvesting. To develop such applications, it is essential to understand both adsorbent-adsorbate and adsorbate-adsorbate interactions, and also the energy required for adsorption/desorption processes of porous material-adsorbate systems, such as zeolites and metal-organic frameworks (MOFs). In this study, we present a technique to characterize the enthalpy of adsorption/desorption of zeolites and MOF-801 with water as an adsorbate by conducting desorption experiments with conventional differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). With this method, the enthalpies of adsorption of previously uncharacterized adsorbents were estimated as a function of both uptake and temperature. Our characterizations indicate that the adsorption enthalpies of type I zeolites can increase to greater than twice the latent heat whereas adsorption enthalpies of MOF-801 are nearly constant for a wide range of vapor uptakes. PMID:26796523

  17. Synthesis and structure of new carbohydrate metal-organic frameworks and inclusion complexes

    NASA Astrophysics Data System (ADS)

    Sha, Jing-Quan; Wu, Lian-He; Li, Shu-Xian; Yang, Xiao-Ning; Zhang, Yu; Zhang, Qian-Nan; Zhu, Pei-Pei

    2015-12-01

    Two new metal-organic framework compounds based on natural β-cyclodextrin molecules (β-CD) and alkali metals (Na+/K+) were synthesized and characterized by elemental analyses, IR, XPRD and 1HNMR. Single-crystal X-ray diffraction analysis reveals that compounds 1 and 2 possess the bowl-like pore and the "8" type double channels configuration. Due to the [blow + channel] double configuration, 5-Fluorouracil (5-FU) and Quercetin inclusion complexes of compound 1 are studied, and the results show that the two kinds of drug with different structure and size can be included into the compound at the same time, which is expected to become a new type of multi-functional green crystalline solid material.

  18. Hypersensitive dual-function luminescence switching of a silver-chalcogenolate cluster-based metal-organic framework

    NASA Astrophysics Data System (ADS)

    Huang, Ren-Wu; Wei, Yong-Sheng; Dong, Xi-Yan; Wu, Xiao-Hui; Du, Chen-Xia; Zang, Shuang-Quan; Mak, Thomas C. W.

    2017-07-01

    Silver(I) chalcogenide/chalcogenolate clusters are promising photofunctional materials for sensing, optoelectronics and solar energy harvesting applications. However, their instability and poor room-temperature luminescent quantum yields have hampered more extensive study. Here, we graft such clusters to adaptable bridging ligands, enabling their interconnection and the formation of rigid metal-organic frameworks. By controlling the spatial separation and orientation of the clusters, they then exhibit enhanced stability (over one year) and quantum yield (12.1%). Ultrafast dual-function fluorescence switching (<1 s) is also achieved, with turn-off triggered by O2 and multicoloured turn-on by volatile organic compounds. Single-crystal X-ray diffraction of the inclusion materials, obtained by single-crystal-to-single-crystal transformation, enables precise determination of the position of the small molecules within the framework, elucidating the switching mechanism. The work enriches the cluster-based metal-organic framework portfolio, bridges the gap between silver chalcogenide/chalcogenolate clusters and metal-organic frameworks, and provides a foundation for further development of functional silver-cluster-based materials.

  19. Hypersensitive dual-function luminescence switching of a silver-chalcogenolate cluster-based metal-organic framework.

    PubMed

    Huang, Ren-Wu; Wei, Yong-Sheng; Dong, Xi-Yan; Wu, Xiao-Hui; Du, Chen-Xia; Zang, Shuang-Quan; Mak, Thomas C W

    2017-07-01

    Silver(i) chalcogenide/chalcogenolate clusters are promising photofunctional materials for sensing, optoelectronics and solar energy harvesting applications. However, their instability and poor room-temperature luminescent quantum yields have hampered more extensive study. Here, we graft such clusters to adaptable bridging ligands, enabling their interconnection and the formation of rigid metal-organic frameworks. By controlling the spatial separation and orientation of the clusters, they then exhibit enhanced stability (over one year) and quantum yield (12.1%). Ultrafast dual-function fluorescence switching (<1 s) is also achieved, with turn-off triggered by O2 and multicoloured turn-on by volatile organic compounds. Single-crystal X-ray diffraction of the inclusion materials, obtained by single-crystal-to-single-crystal transformation, enables precise determination of the position of the small molecules within the framework, elucidating the switching mechanism. The work enriches the cluster-based metal-organic framework portfolio, bridges the gap between silver chalcogenide/chalcogenolate clusters and metal-organic frameworks, and provides a foundation for further development of functional silver-cluster-based materials.

  20. Composite Membranes for CO2 Capture: High Performance Metal Organic Frameworks/Polymer Composite Membranes for Carbon Dioxide Capture

    SciTech Connect

    2010-07-01

    IMPACCT Project: A team of six faculty members at Georgia Tech are developing an enhanced membrane by fitting metal organic frameworks, compounds that show great promise for improved carbon capture, into hollow fiber membranes. This new material would be highly efficient at removing CO2 from the flue gas produced at coal-fired power plants. The team is analyzing thousands of metal organic frameworks to identify those that are most suitable for carbon capture based both on their ability to allow coal exhaust to pass easily through them and their ability to select CO2 from that exhaust for capture and storage. The most suitable frameworks would be inserted into the walls of the hollow fiber membranes, making the technology readily scalable due to their high surface area. This composite membrane would be highly stable, withstanding the harsh gas environment found in coal exhaust.

  1. Alkylamine-tethered stable metal-organic framework for CO(2) capture from flue gas.

    PubMed

    Hu, Yingli; Verdegaal, Wolfgang M; Yu, Shu-Hong; Jiang, Hai-Long

    2014-03-01

    Different alkylamine molecules were post-synthetically tethered to the unsaturated Cr(III) centers in the metal-organic framework MIL-101. The resultant metal-organic frameworks show almost no N2 adsorption with significantly enhanced CO2 capture under ambient conditions as a result of the interaction between amine groups and CO2 molecules. Given the extraordinary stability, high CO2 uptake, ultrahigh CO2 /N2 selectivity, and mild regeneration energy, MIL-101-diethylenetriamine holds exceptional promise for post-combustion CO2 capture and CO2 /N2 separation.

  2. Tunable electrical conductivity in metal-organic framework thin film devices

    SciTech Connect

    Talin, Albert Alec; Allendorf, Mark D.; Stavila, Vitalie; Leonard, Francois

    2016-08-30

    A composition including a porous metal organic framework (MOF) including an open metal site and a guest species capable of charge transfer that can coordinate with the open metal site, wherein the composition is electrically conductive. A method including infiltrating a porous metal organic framework (MOF) including an open metal site with a guest species that is capable of charge transfer; and coordinating the guest species to the open metal site to form a composition including an electrical conductivity greater than an electrical conductivity of the MOF.

  3. Multirate delivery of multiple therapeutic agents from metal-organic frameworks

    SciTech Connect

    McKinlay, Alistair C.; Allan, Phoebe K.; Renouf, Catherine L.; Duncan, Morven J.; Wheatley, Paul S.; Warrender, Stewart J.; Dawson, Daniel; Ashbrook, Sharon E.; Gil, Barbara; Marszalek, Bartosz; Düren, Tina; Williams, Jennifer J.; Charrier, Cedric; Mercer, Derry K.; Teat, Simon J.; Morris, Russell E.

    2014-12-01

    The highly porous nature of metal-organic frameworks (MOFs) offers great potential for the delivery of therapeutic agents. Here, we show that highly porous metal-organic frameworks can be used to deliver multiple therapeutic agents—a biologically active gas, an antibiotic drug molecule, and an active metal ion—simultaneously but at different rates. The possibilities offered by delivery of multiple agents with different mechanisms of action and, in particular, variable timescales may allow new therapy approaches. Here, we show that the loaded MOFs are highly active against various strains of bacteria.

  4. Multirate delivery of multiple therapeutic agents from metal-organic frameworks

    DOE PAGES

    McKinlay, Alistair C.; Allan, Phoebe K.; Renouf, Catherine L.; ...

    2014-12-01

    The highly porous nature of metal-organic frameworks (MOFs) offers great potential for the delivery of therapeutic agents. Here, we show that highly porous metal-organic frameworks can be used to deliver multiple therapeutic agents—a biologically active gas, an antibiotic drug molecule, and an active metal ion—simultaneously but at different rates. The possibilities offered by delivery of multiple agents with different mechanisms of action and, in particular, variable timescales may allow new therapy approaches. Here, we show that the loaded MOFs are highly active against various strains of bacteria.

  5. Tunable electrical conductivity in metal-organic framework thin film devices

    SciTech Connect

    Talin, Albert Alec; Allendorf, Mark D.; Stavila, Vitalie; Leonard, Francois

    2016-05-24

    A composition including a porous metal organic framework (MOF) including an open metal site and a guest species capable of charge transfer that can coordinate with the open metal site, wherein the composition is electrically conductive. A method including infiltrating a porous metal organic framework (MOF) including an open metal site with a guest species that is capable of charge transfer; and coordinating the guest species to the open metal site to form a composition including an electrical conductivity greater than an electrical conductivity of the MOF.

  6. Selective Catalysis in Nanoparticle Metal-Organic Framework Composites

    NASA Astrophysics Data System (ADS)

    Stephenson, Casey Justin

    The design of highly selective catalysts are becoming increasingly important, especially as chemical and pharmaceutical industries seek to improve atom economy and minimize energy intensive separations that are often required to separate side products from the desired product. Enzymes are among the most selective of all catalysts, generally operating through molecular recognition whereby an active site analogous to a lock and the substrate is analogous to a key. The assembly of a porous, crystalline material around a catalytically active metal particle could serve as an artificial enzyme. In this vein, we first synthesized the polyvinylpyrrolidone (PVP) coated nanoparticles of interest and then encapsulated them within zeolitic imidazolate framework 8 or ZIF-8. 2.8 nm Pt-PVP nanoparticles, which were encapsulated within ZIF-8 to form Pt ZIF-8 composite. Pt ZIF-8 was inactive for the hydrogenation of cyclic olefins such as cis-cyclooctene and cis-cyclohexene while the composite proved to be a highly selective catalyst for the hydrogenation of terminal olefins, hydrogenating trans-1,3-hexadiene to 3-hexene in 95% selectivity after 24 hours under 1 bar H2. We extended our encapsulation method to sub-2 nm Au nanoparticles to form Au ZIF-8. Au ZIF-8 served as a highly chemoselective catalyst for the hydrogenation of crotonaldehyde an alpha,beta-unsaturated aldehyde, to crotyl alcohol an alpha,beta-unsaturated alcohol, in 90-95% selectivity. In order to investigate nanoparticle size effects on selectivity, 6-10 nm Au nanoparticles were encapsulated within ZIF-8 to form Au6 ZIF-8. Control catalysts with nanoparticles supported on the surface of ZIF-8 were synthesized as well, Au/ZIF-8 and Au6/ZIF-8. Au6 ZIF-8 hydrogenated crotonaldehyde in 85% selectivity towards the unsaturated alcohol. Catalysts with nanoparticles supported on the exterior of ZIF-8 were far less selective towards the unsaturated alcohol. Post-catalysis transmission electron microscopy analysis of Au ZIF

  7. Design of Multi-Decker Incorporated Metal Organic Frameworks for Hydrogen Storage

    NASA Astrophysics Data System (ADS)

    Boggavarapu, Kiran; Kandalam, Anil

    2009-03-01

    Metal Organic Frameworks (MOFs) are a new class of rationally designed microporous hybrid (organic-inorganic) materials. They have recently gained attention as potential hydrogen storage systems with gravimetric density meeting the DOE 2015 targets of 9 wt%. However, due to weak interaction between the molecular hydrogen and the host MOF (see figure), high pressures are required to reach the target storage levels. Recently, multi-decker organometallic complexes are shown to exhibit the ideal thermodynamics and kinetics for hydrogen storage. However, it is not clear if these multi-decker complexes can retain their hydrogen storage capability when assembled into a bulk-material. In this presentation, we investigate the hydrogen storage capability of a new class of materials by combining the strengths of MOFs and decker complexes. An ideal way to integrate these two systems is to incorporate the multi-deckers into the structural framework of MOFs. In these hybrid materials, the multi-decker units are expected to maintain their structural integrity and there by retaining the hydrogen storage capacity with an added advantage of being a part of stable porous MOF back-bone.

  8. Functionalization of Metal-Organic Frameworks for Enhanced Stability under Humid Carbon Dioxide Capture Conditions.

    PubMed

    Andirova, Dinara; Lei, Yu; Zhao, Xiaodan; Choi, Sunho

    2015-10-26

    Metal-organic frameworks (MOFs) have been highlighted recently as promising materials for CO2 capture. However, in practical CO2 capture processes, such as capture from flue gas or ambient air, the adsorption properties of MOFs tend to be harmed by the presence of moisture possibly because of the hydrophilic nature of the coordinatively unsaturated sites (CUSs) within their framework. In this work, the CUSs of the MOF framework are functionalized with amine-containing molecules to prevent structural degradation in a humid environment. Specifically, the framework of the magnesium dioxybenzenedicarboxylate (Mg/DOBDC) MOF was functionalized with ethylenediamine (ED) molecules to make the overall structure less hydrophilic. Structural analysis after exposure to high-temperature steam showed that the ED-functionalized Mg/DOBDC (ED-Mg/DOBDC) is more stable under humid conditions, than Mg/DOBDC, which underwent drastic structural changes. ED-Mg/DOBDC recovered its CO2 adsorption capacity and initial adsorption rate quite well as opposed to the original Mg/DOBDC, which revealed a significant reduction in its capture capacity and kinetics. These results suggest that the amine-functionalization of the CUSs is an effective way to enhance the structural stability of MOFs as well as their capture of humid CO2 .

  9. High performance hydrogen storage from Be-BTB metal-organic framework at room temperature.

    PubMed

    Lim, Wei-Xian; Thornton, Aaron W; Hill, Anita J; Cox, Barry J; Hill, James M; Hill, Matthew R

    2013-07-09

    The metal-organic framework beryllium benzene tribenzoate (Be-BTB) has recently been reported to have one of the highest gravimetric hydrogen uptakes at room temperature. Storage at room temperature is one of the key requirements for the practical viability of hydrogen-powered vehicles. Be-BTB has an exceptional 298 K storage capacity of 2.3 wt % hydrogen. This result is surprising given that the low adsorption enthalpy of 5.5 kJ mol(-1). In this work, a combination of atomistic simulation and continuum modeling reveals that the beryllium rings contribute strongly to the hydrogen interaction with the framework. These simulations are extended with a thermodynamic energy optimization (TEO) model to compare the performance of Be-BTB to a compressed H2 tank and benchmark materials MOF-5 and MOF-177 in a MOF-based fuel cell. Our investigation shows that none of the MOF-filled tanks satisfy the United States Department of Energy (DOE) storage targets within the required operating temperatures and pressures. However, the Be-BTB tank delivers the most energy per volume and mass compared to the other material-based storage tanks. The pore size and the framework mass are shown to be contributing factors responsible for the superior room temperature hydrogen adsorption of Be-BTB.

  10. Metal-organic framework templated synthesis of Fe2O3/TiO2 nanocomposite for hydrogen production.

    PubMed

    deKrafft, Kathryn E; Wang, Cheng; Lin, Wenbin

    2012-04-17

    A new metal-organic framework (MOF)-templated method has been developed for the synthesis of a metal oxide nanocomposite with interesting photophysical properties. Fe-containing nanoscale MOFs are coated with amorphous titania, then calcined to produce crystalline Fe(2)O(3)/TiO(2) composite nanoparticles. This material enables photocatalytic hydrogen production from water using visible light, which cannot be achieved by either Fe(2)O(3) or TiO(2) alone or a mixture of the two.

  11. Protecting group and switchable pore-discriminating adsorption properties of a hydrophilic-hydrophobic metal-organic framework.

    PubMed

    Mohideen, M Infas H; Xiao, Bo; Wheatley, Paul S; McKinlay, Alistair C; Li, Yang; Slawin, Alexandra M Z; Aldous, David W; Cessford, Naomi F; Düren, Tina; Zhao, Xuebo; Gill, Rachel; Thomas, K Mark; Griffin, John M; Ashbrook, Sharon E; Morris, Russell E

    2011-04-01

    Formed by linking metals or metal clusters through organic linkers, metal-organic frameworks are a class of solids with structural and chemical properties that mark them out as candidates for many emerging gas storage, separation, catalysis and biomedical applications. Important features of these materials include their high porosity and their flexibility in response to chemical or physical stimuli. Here, a copper-based metal-organic framework has been prepared in which the starting linker (benzene-1,3,5-tricarboxylic acid) undergoes selective monoesterification during synthesis to produce a solid with two different channel systems, lined by hydrophilic and hydrophobic surfaces, respectively. The material reacts differently to gases or vapours of dissimilar chemistry, some stimulating subtle framework flexibility or showing kinetic adsorption effects. Adsorption can be switched between the two channels by judicious choice of the conditions. The monoesterified linker is recoverable in quantitative yield, demonstrating possible uses of metal-organic frameworks in molecular synthetic chemistry as 'protecting groups' to accomplish selective transformations that are difficult using standard chemistry techniques.

  12. Protecting group and switchable pore-discriminating adsorption properties of a hydrophilic-hydrophobic metal-organic framework

    NASA Astrophysics Data System (ADS)

    Mohideen, M. Infas H.; Xiao, Bo; Wheatley, Paul S.; McKinlay, Alistair C.; Li, Yang; Slawin, Alexandra M. Z.; Aldous, David W.; Cessford, Naomi F.; Düren, Tina; Zhao, Xuebo; Gill, Rachel; Thomas, K. Mark; Griffin, John M.; Ashbrook, Sharon E.; Morris, Russell E.

    2011-04-01

    Formed by linking metals or metal clusters through organic linkers, metal-organic frameworks are a class of solids with structural and chemical properties that mark them out as candidates for many emerging gas storage, separation, catalysis and biomedical applications. Important features of these materials include their high porosity and their flexibility in response to chemical or physical stimuli. Here, a copper-based metal-organic framework has been prepared in which the starting linker (benzene-1,3,5-tricarboxylic acid) undergoes selective monoesterification during synthesis to produce a solid with two different channel systems, lined by hydrophilic and hydrophobic surfaces, respectively. The material reacts differently to gases or vapours of dissimilar chemistry, some stimulating subtle framework flexibility or showing kinetic adsorption effects. Adsorption can be switched between the two channels by judicious choice of the conditions. The monoesterified linker is recoverable in quantitative yield, demonstrating possible uses of metal-organic frameworks in molecular synthetic chemistry as ‘protecting groups’ to accomplish selective transformations that are difficult using standard chemistry techniques.

  13. Structural Origins of Scintillation: Metal Organic Frameworks as a Nanolaboratory

    DTIC Science & Technology

    2016-06-01

    use. The results of this project provide fundamental insight into the electronic and structural features of novel scintillating materials known as...flexible structure, present unique advantages for radiation detection over existing organic scintillator materials . In addition, MOFs provide a...luminescence decay in MOFs, and will, if controlled, lead to MOFs optimized for particle identification and discrimination? (3) Can nanoporous MOFs, by

  14. Tuning the Adsorption-Induced Phase Change in the Flexible Metal-Organic Framework Co(bdp).

    PubMed

    Taylor, Mercedes K; Runčevski, Tomče; Oktawiec, Julia; Gonzalez, Miguel I; Siegelman, Rebecca L; Mason, Jarad A; Ye, Jinxing; Brown, Craig M; Long, Jeffrey R

    2016-11-16

    Metal-organic frameworks that flex to undergo structural phase changes upon gas adsorption are promising materials for gas storage and separations, and achieving synthetic control over the pressure at which these changes occur is crucial to the design of such materials for specific applications. To this end, a new family of materials based on the flexible metal-organic framework Co(bdp) (bdp(2-) = 1,4-benzenedipyrazolate) has been prepared via the introduction of fluorine, deuterium, and methyl functional groups on the bdp(2-) ligand, namely, Co(F-bdp), Co(p-F2-bdp), Co(o-F2-bdp), Co(D4-bdp), and Co(p-Me2-bdp). These frameworks are isoreticular to the parent framework and exhibit similar structural flexibility, transitioning from a low-porosity, collapsed phase to high-porosity, expanded phases with increasing gas pressure. Powder X-ray diffraction studies reveal that fluorination of the aryl ring disrupts edge-to-face π-π interactions, which work to stabilize the collapsed phase at low gas pressures, while deuteration preserves these interactions and methylation strengthens them. In agreement with these observations, high-pressure CH4 adsorption isotherms show that the pressure of the CH4-induced framework expansion can be systematically controlled by ligand functionalization, as materials without edge-to-face interactions in the collapsed phase expand at lower CH4 pressures, while frameworks with strengthened edge-to-face interactions expand at higher pressures. Importantly, this work puts forth a general design strategy relevant to many other families of flexible metal-organic frameworks, which will be a powerful tool in optimizing these phase-change materials for industrial applications.

  15. Carborane-Based Metal-Organic Framework with High Methane and Hydrogen Storage Capacities

    DTIC Science & Technology

    2013-01-01

    REPORT Carborane-Based Metal –Organic Framework with High Methane and Hydrogen Storage Capacities 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: A Cu...Carborane-Based Metal –Organic Framework with High Methane and Hydrogen Storage Capacities Report Title ABSTRACT A Cu?carborane-based metal ?organic...Based Metal −Organic Framework with High Methane and Hydrogen Storage Capacities Robert D. Kennedy,† Vaiva Krungleviciute,‡,§ Daniel J. Clingerman,† Joseph

  16. Methane storage in flexible metal-organic frameworks with intrinsic thermal management

    NASA Astrophysics Data System (ADS)

    Mason, Jarad A.; Oktawiec, Julia; Taylor, Mercedes K.; Hudson, Matthew R.; Rodriguez, Julien; Bachman, Jonathan E.; Gonzalez, Miguel I.; Cervellino, Antonio; Guagliardi, Antonietta; Brown, Craig M.; Llewellyn, Philip L.; Masciocchi, Norberto; Long, Jeffrey R.

    2015-11-01

    As a cleaner, cheaper, and more globally evenly distributed fuel, natural gas has considerable environmental, economic, and political advantages over petroleum as a source of energy for the transportation sector. Despite these benefits, its low volumetric energy density at ambient temperature and pressure presents substantial challenges, particularly for light-duty vehicles with little space available for on-board fuel storage. Adsorbed natural gas systems have the potential to store high densities of methane (CH4, the principal component of natural gas) within a porous material at ambient temperature and moderate pressures. Although activated carbons, zeolites, and metal-organic frameworks have been investigated extensively for CH4 storage, there are practical challenges involved in designing systems with high capacities and in managing the thermal fluctuations associated with adsorbing and desorbing gas from the adsorbent. Here, we use a reversible phase transition in a metal-organic framework to maximize the deliverable capacity of CH4 while also providing internal heat management during adsorption and desorption. In particular, the flexible compounds Fe(bdp) and Co(bdp) (bdp2- = 1,4-benzenedipyrazolate) are shown to undergo a structural phase transition in response to specific CH4 pressures, resulting in adsorption and desorption isotherms that feature a sharp ‘step’. Such behaviour enables greater storage capacities than have been achieved for classical adsorbents, while also reducing the amount of heat released during adsorption and the impact of cooling during desorption. The pressure and energy associated with the phase transition can be tuned either chemically or by application of mechanical pressure.

  17. Methane storage in flexible metal-organic frameworks with intrinsic thermal management.

    PubMed

    Mason, Jarad A; Oktawiec, Julia; Taylor, Mercedes K; Hudson, Matthew R; Rodriguez, Julien; Bachman, Jonathan E; Gonzalez, Miguel I; Cervellino, Antonio; Guagliardi, Antonietta; Brown, Craig M; Llewellyn, Philip L; Masciocchi, Norberto; Long, Jeffrey R

    2015-11-19

    As a cleaner, cheaper, and more globally evenly distributed fuel, natural gas has considerable environmental, economic, and political advantages over petroleum as a source of energy for the transportation sector. Despite these benefits, its low volumetric energy density at ambient temperature and pressure presents substantial challenges, particularly for light-duty vehicles with little space available for on-board fuel storage. Adsorbed natural gas systems have the potential to store high densities of methane (CH4, the principal component of natural gas) within a porous material at ambient temperature and moderate pressures. Although activated carbons, zeolites, and metal-organic frameworks have been investigated extensively for CH4 storage, there are practical challenges involved in designing systems with high capacities and in managing the thermal fluctuations associated with adsorbing and desorbing gas from the adsorbent. Here, we use a reversible phase transition in a metal-organic framework to maximize the deliverable capacity of CH4 while also providing internal heat management during adsorption and desorption. In particular, the flexible compounds Fe(bdp) and Co(bdp) (bdp(2-) = 1,4-benzenedipyrazolate) are shown to undergo a structural phase transition in response to specific CH4 pressures, resulting in adsorption and desorption isotherms that feature a sharp 'step'. Such behaviour enables greater storage capacities than have been achieved for classical adsorbents, while also reducing the amount of heat released during adsorption and the impact of cooling during desorption. The pressure and energy associated with the phase transition can be tuned either chemically or by application of mechanical pressure.

  18. Upconversion fluorescence metal-organic frameworks thermo-sensitive imprinted polymer for enrichment and sensing protein.

    PubMed

    Guo, Ting; Deng, Qiliang; Fang, Guozhen; Gu, Dahai; Yang, Yukun; Wang, Shuo

    2016-05-15

    A novel fluorescence material with thermo-sensitive for the enrichment and sensing of protein was successfully prepared by combining molecular imprinting technology with upconversion nanoparticles (UCNPs) and metal-organic frameworks (MOFs). Herein, the UCNPs acted as signal reporter for composite materials because of its excellent fluorescence property and chemical stability. MOFs were introduced to molecularly imprinted polymer (MIP) due to its high specific surface area which increases the rate of mass transfer relative to that of traditional bulk MIP. The thermo-sensitive imprinted material which allows for swelling and shrinking with response to temperature changes was prepared by choosing Bovine hemoglobin (BHB) as the template, N-isopropyl acrylamide (NIPAAM) as the temperature-sensitive functional monomer and N,N-methylenebisacrylamide (MBA) as the cross-linker. The recognition characterizations of imprinted material-coated UCNPs/MOFs (UCNPs/MOFs/MIP) were evaluated, and the results showed that the fluorescence intensity of UCNPs/MOFs/MIP reduced gradually with the increase of BHB concentration. The fluorescence material was response to the temperature. The adsorption capacity was as much as 167.6 mg/g at 28°C and 101.2mg/g at 44°C, which was higher than that of traditional MIP. Therefore, this new fluorescence material for enrichment and sensing protein is very promising for future applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Incorporation of Molecular Catalysts in Metal-Organic Frameworks for Highly Efficient Heterogeneous Catalysis.

    PubMed

    Wu, Chuan-De; Zhao, Min

    2017-03-03

    Porous metal-organic frameworks (MOFs) are built from periodically alternate organic moieties and metal ions/clusters. The unique features of the open framework structures, the high surface areas, the permanent porosity, and the appropriate hydrophilic and hydrophobic pore nature mean that MOF materials are a class of ideal host matrices for immobilization of molecular catalysts. The emerging porous materials can not only retain but are also able to enhance the catalytic functions of the single individuals. MOF catalysts have the following super characters: i) uniformly dispersed catalytic sites on the pore surfaces to improve the utility, ii) appropriate hydrophilic and hydrophobic pore nature to facilitate the recognition and transportation of reactant and product molecules, iii) a collaborative microenvironment to realize synergistic catalysis, and iv) simple separation and recovery for long-term usage. Accompanying the development of the synthetic strategies and the technologies for the characterization of MOF materials, MOF catalysis has undergone an upsurge, which has transcended the stage of opportunism. Here, the rational design and synthesis of MOF catalysts are discussed, along with the key factors of active sites, microenvironments, and transmission channels that lead to the distinct catalytic properties of MOF catalysts.

  20. Structuring of metal-organic frameworks at the mesoscopic/macroscopic scale.

    PubMed

    Furukawa, Shuhei; Reboul, Julien; Diring, Stéphane; Sumida, Kenji; Kitagawa, Susumu

    2014-08-21

    The assembly of metal ions with organic ligands through the formation of coordination bonds gives crystalline framework materials, known as metal-organic frameworks (MOFs), which recently emerged as a new class of porous materials. Besides the structural designability of MOFs at the molecular length scale, the researchers in this field very recently made important advances in creating more complex architectures at the mesoscopic/macroscopic scale, in which MOF nanocrystals are used as building units to construct higher-order superstructures. The structuring of MOFs in such a hierarchical order certainly opens a new opportunity to improve the material performance via design of the physical form rather than altering the chemical component. This review highlights these superstructures and their applications by categorizing them into four dimensionalities, zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) superstructures. Because the key issue for structuring of MOFs is to spatially control the nucleation process in desired locations, this review conceptually categorizes the available synthetic methodologies from the viewpoint of the reaction system.