Sample records for dimethoxymethane
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Starikova, O.F.; Gurvich, Y.A.; Kumok, S.T.
1985-12-20
The authors explain how di(hydroxydialkylaryl) derivatives of methane play an important role in the inhibition of oxidation processes in polymers, oils, fuels, and other organic materials. They investigate the reaction of 4-methyl-2-tert-butylphenol with dimethoxymethane, and established that the reaction mass contained 2-methoxymethyl-4-6-tert-butylphenol. The formation and the transformations of 2-methoxymethyl-4-methyl-6-tert-butylphenol do not have a significant effect on the synthesis of di(2-hydroxy-5-methyl-3-tert-butylphenyl) methane from 4-methyl-2-tert-butyl-phenol and dimethoxymethane.
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2001-04-01
Dimethoxymethane DNPH Dinitrophenylhydrazine DOE Department of Energy DPF Diesel Particulate Filter EGR Exhaust Gas Recirculation FT-100 Neat Fischer-Tropsch...cartridge containing silica impregnated with 2,4- dinitrophenylhydrazine (DNPH), Figure 4. A metered volume of the background air was pulled through another
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One-pot conversion of biomass-derived xylose and furfural into levulinate esters via acid catalysis.
Hu, Xun; Jiang, Shengjuan; Wu, Liping; Wang, Shuai; Li, Chun-Zhu
2017-03-07
Direct conversion of biomass-derived xylose and furfural into levulinic acid, a platform molecule, via acid-catalysis has been accomplished for the first time in dimethoxymethane/methanol. Dimethoxymethane acted as an electrophile to transform furfural into 5-hydroxymethylfurfural (HMF). Methanol suppressed both the polymerisation of the sugars/furans and the Aldol condensation of levulinic acid/ester.
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Metal cleaners contain organic compounds called hydrocarbons, including: 1,2-butylene oxide Boric acid Cocoyl sarcosine Dicarboxylic fatty acid Dimethoxymethane Dodecanedioic acid N-propyl bromide Sodium hydroxide T-butanol
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Haichao; Iglesia, Enrique
RuO2 domains supported on SnO2, ZrO2, TiO2, Al2O3, and SiO2 catalyze the oxidative conversion of methanol to formaldehyde, methylformate, and dimethoxymethane with unprecedented rates and high combined selectivity (>99 percent) and yield at low temperatures (300-400 K). Supports influence turnover rates and the ability of RuO2 domains to undergo redox cycles required for oxidation turnovers. Oxidative dehydrogenation turnover rates and rates of stoichiometric reduction of RuO2 in H2 increased in parallel when RuO2 domains were dispersed on more reducible supports. These support effects, the kinetic effects of CH3OH and O2 on reaction rates, and the observed kinetic isotope effects withmore » CH3OD and CD3OD reactants are consistent with a sequence of elementary steps involving kinetically relevant H-abstraction from adsorbed methoxide species using lattice oxygen atoms and with methoxide formation in quasi-equilibrated CH3OH dissociation on nearly stoichiometric RuO2 surfaces. Anaerobic transient experiments confirmed that CH3OH oxidation to HCHO requires lattice oxygen atoms and that selectivities are not influenced by the presence of O2. Residence time effects on selectivity indicate that secondary HCHO-CH3OH acetalization reactions lead to hemiacetal or methoxymethanol intermediates that convert to dimethoxymethane in reactions with CH3OH on support acid sites or dehydrogenate to form methylformate on RuO2 and support redox sites. These conclusions are consistent with the tendency of Al2O3 and SiO2 supports to favor dimethoxymethane formation, while SnO2, ZrO2, and TiO2 preferentially form methylformate. These support effects on secondary reactions were confirmed by measured CH3OH oxidation rates and selectivities on physical mixtures of supported RuO2 catalysts and pure supports. Ethanol also reacts on supported RuO2 domains to form predominately acetaldehyde and diethoxyethane at 300-400 K. The bifunctional nature of these reaction pathways and the remarkable ability of RuO2-based catalysts to oxidize CH3OH to HCHO at unprecedented low temperatures introduce significant opportunities for new routes to complex oxygenates, including some containing C-C bonds, using methanol or ethanol as intermediates derived from natural gas or biomass.« less
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Thenert, Katharina; Beydoun, Kassem; Wiesenthal, Jan; Leitner, Walter; Klankermayer, Jürgen
2016-09-26
The synthesis of dimethoxymethane (DMM) by a multistep reaction of methanol with carbon dioxide and molecular hydrogen is reported. Using the molecular catalyst [Ru(triphos)(tmm)] in combination with the Lewis acid Al(OTf)3 resulted in a versatile catalytic system for the synthesis of various dialkoxymethane ethers. This new catalytic reaction provides the first synthetic example for the selective conversion of carbon dioxide and hydrogen into a formaldehyde oxidation level, thus opening access to new molecular structures using this important C1 source. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Electrochemical oxidation of methanol using dppm-bridged Ru/Pd, Ru/Pt and Ru/Au catalysts.
Yang, Ying; McElwee-White, Lisa
2004-08-07
The electrochemical oxidation of methanol was carried out using a series of dppm-bridged Ru/Pd, Ru/Pt and Ru/Au heterobimetallic complexes as catalysts. The major oxidation products were formaldehyde dimethyl acetal (dimethoxymethane, DMM) and methyl formate (MF). The Ru/Pd and Ru/Pt bimetallic catalysts generally afforded lower product ratios of DMM/MF and higher current efficiencies than the Ru/Au catalysts. The Ru/Au bimetallics exhibited product ratios and current efficiencies similar to those obtained from the Ru mononuclear compound CpRu(PPh(3))(2)Cl. Increasing the methanol concentration afforded higher current efficiencies, while the addition of water to the samples shifted the product distribution toward the more highly oxidized product, MF.
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Organic fuel cell methods and apparatus
NASA Technical Reports Server (NTRS)
Narayanan, Sekharipuram R. (Inventor); Frank, Harvey A. (Inventor); Halpert, Gerald (Inventor); Surampudi, Subbarao (Inventor); Prakash, G. K. Surya (Inventor); Vamos, Eugene (Inventor); Olah, George A. (Inventor)
2001-01-01
A liquid organic fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.
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Organic fuel cell methods and apparatus
NASA Technical Reports Server (NTRS)
Surampudi, Subbarao (Inventor); Narayanan, Sekharipuram R. (Inventor); Vamos, Eugene (Inventor); Halpert, Gerald (Inventor); Olah, George A. (Inventor); Frank, Harvey A. (Inventor); Prakash, G. K. Surya (Inventor)
2004-01-01
A liquid organic, fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.
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Organic fuel cell methods and apparatus
NASA Technical Reports Server (NTRS)
Frank, Harvey A. (Inventor); Halpert, Gerald (Inventor); Surampudi, Subbarao (Inventor); Olah, George A. (Inventor); Vamos, Eugene (Inventor); Narayanan, Sekharipuram R. (Inventor); Prakash, G. K. Surya (Inventor)
2008-01-01
A liquid organic, fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.
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Aqueous liquid feed organic fuel cell using solid polymer electrolyte membrane
NASA Technical Reports Server (NTRS)
Olah, George A. (Inventor); Surampudi, Subbarao (Inventor); Vamos, Eugene (Inventor); Halpert, Gerald (Inventor); Narayanan, Sekharipuram R. (Inventor); Frank, Harvey A. (Inventor); Prakash, G. K. Surya (Inventor)
1997-01-01
A liquid organic fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.
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Engeldinger, Jana; Richter, Manfred; Bentrup, Ursula
2012-02-21
The simultaneous combination of steady state isotopic transient kinetic analysis (SSITKA) with diffuse reflectance Fourier transform spectroscopy (DRIFTS) and mass spectrometric (MS) analysis was applied to study the oxidative carbonylation of methanol (MeOH) to dimethyl carbonate (DMC) on a CuY zeolite catalyst prepared by incipient-wetness impregnation of commercial zeolite NH(4)-Y. The interaction of the catalyst with different reactants and reactant mixtures (O(2), CO, CO/O(2), MeOH/O(2), MeOH/CO, and MeOH/CO/O(2)) was studied in detail using (16)O(2)/(18)O(2) as well as (12)CO/(13)CO containing gas mixtures. DMC is produced via a monodentate monomethyl carbonate (MMC) species as intermediate which is formed by the concerted action of adsorbed methoxide and CO with gas phase MeOH. Adsorbed bidentate MMC species were found to be inactive. Lattice oxygen supplied by CuO(x) species is involved in the formation of MMC. Gas phase oxygen is needed to re-oxidize the catalyst but favours also the oxidation of CO to CO(2) and unselective oxidation reactions of MeOH to methyl formate, dimethoxymethane, and CO(2). The appropriate choice of reaction temperature and of the oxygen content in the reactant gas mixture was found to be indispensable for reaching high DMC selectivities.
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Shang, Barry Z; Wang, Zuowei; Larson, Ronald G
2008-03-13
We have performed atomistic molecular dynamics simulations of an anionic sodium dodecyl sulfate (SDS) micelle and a nonionic poly(ethylene oxide) (PEO) polymer in aqueous solution. The micelle consisted of 60 surfactant molecules, and the polymer chain lengths varied from 20 to 40 monomers. The force field parameters for PEO were adjusted by using 1,2-dimethoxymethane (DME) as a model compound and matching its hydration enthalpy and conformational behavior to experiment. Excellent agreement with previous experimental and simulation work was obtained through these modifications. The simulated scaling behavior of the PEO radius of gyration was also in close agreement with experimental results. The SDS-PEO simulations show that the polymer resides on the micelle surface and at the hydrocarbon-water interface, leading to a selective reduction in the hydrophobic contribution to the solvent-accessible surface area of the micelle. The association is mainly driven by hydrophobic interactions between the polymer and surfactant tails, while the interaction between the polymer and sulfate headgroups on the micelle surface is weak. The 40-monomer chain is mostly wrapped around the micelle, and nearly 90% of the monomers are adsorbed at low PEO concentration. Simulations were also performed with multiple 20-monomer chains, and gradual addition of polymer indicates that about 120 monomers are required to saturate the micelle surface. The stoichiometry of the resulting complex is in close agreement with experimental results, and the commonly accepted "beaded necklace" structure of the SDS-PEO complex is recovered by our simulations.
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Biofiltration of high formaldehyde loads with ozone additions in long-term operation.
Maldonado-Diaz, G; Arriaga, S
2015-01-01
Formaldehyde (FA) biofiltration was evaluated over 310 days with and without ozone addition. Without ozone, the biofilter was able to treat formaldehyde at inlet loads (ILs) lower than 40 g m(-3) h(-1), maintaining, under this condition, an average removal efficiency (RE) of 88 % for a few days before collapsing to zero. The continuous addition of ozone (90 ppbv) helped to recover the RE from zero to 98 ± 2 % and made it possible to operate at an IL of 40 g m(-3) h(-1) for long periods of operation (107 days). Furthermore, the ozone addition aided in operating the biofilter at a formaldehyde IL of up to 120 g m(-3) h(-1) values that have never before been reached. GC-mass spectrometry (MS) analysis showed that dimethoxymethane was the common compound in leachate during the performance decay. Also, the addition of ozone aided in maintaining an optimal pH in the biofilter with values between 7.5 and 8.2, due to the carbonate species formed during the ozone reactions with formaldehyde and its by-products. Thus, the pH control was confirmed and the alkalinity of the biofilter increased from 334.1 ± 100.3 to 1450 ± 127 mg CaCO3 L(-1) when ozone was added. Ozone addition diminished the exopolymeric substances (EPS) content of biofilm and biofilm thickness without affecting cell viability. Kinetic parameters suggested that the best conditions for carrying out FA biofiltration were reached under ozone addition. The addition of ozone during formaldehyde biofiltration could be a good strategy to maintain the pH and the steady state of the system under high ILs and for long periods of operation.
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Chemical and electrochemical oxidation of small organic molecules
NASA Astrophysics Data System (ADS)
Smart, Marshall C.
Direct oxidation fuel cells using proton-exchange membrane electrolytes have long been recognized as being an attractive mode of power generation. The current work addresses the electro-oxidation characteristics of a number of potential fuels on Pt-based electrodes which can be used in direct oxidation fuel cells, including hydrocarbons and oxygenated molecules, such as alcohols, formates, ethers, and acetals. Promising alternative fuels which were identified, such as trimethoxymethane and dimethoxymethane, were then investigated in liquid-feed PEM-based fuel cells. In addition to investigating the nature of the anodic electro-oxidation of organic fuels, effort was also devoted to developing novel polymer electrolyte membranes which have low permeability to organic molecules, such as methanol. This research was initiated with the expectation of reducing the extent of fuel crossover from the anode to the cathode in the liquid-feed design fuel cell which results in lower fuel efficiency and performance. Other work involving efforts to improve the performance of direct oxidation fuel cell includes research focused upon improving the kinetics of oxygen reduction. There is continued interest in the identification of new, safe, non-toxic, and inexpensive reagents which can be used in the oxidation of organic compounds. Urea-hydrogen peroxide (UHP), a hydrogen bonded adduct, has been shown to serve as a valuable source of hydrogen peroxide in a range of reactions. UHP has been shown to be ideal for the monohydroxylation of aromatics, including toluene, ethylbenzene, p-xylene, m-xylene, and mesitylene, as well as benzene, in the presence of trifluoromethanesulfonic acid. It was also found that aniline was converted to a mixture containing primarily azobenzene, azoxybenzene and nitrobenzene when reacted with UHP in glacial acetic acid. A number of aniline derivatives have been investigated and it was observed that the corresponding azoxybenzene derivatives could be generated as the major products in good to excellent yields. The oxidation of other organic substrates was also investigated using urea-hydrogen peroxide as an oxidation reagent, including cyclohexylamine, 1-adamantaneamine, and adamantane.