107-31-3Relevant articles and documents
Effects of the MoO3 structure of Mo-Sn catalysts on dimethyl ether oxidation to methyl formate under mild conditions
Liu, Guangbo,Zhang, Qingde,Han, Yizhuo,Tsubaki, Noritatsu,Tan, Yisheng
, p. 1057 - 1064 (2015)
The selective oxidation of dimethyl ether (DME) to methyl formate (MF) was conducted in a fixed-bed reactor over the MoO3-SnO2 catalysts with different Mo/Sn ratios. The MF selectivity reached 94.1% and the DME conversion was 33.9% without the formation of COx over the MoSn catalyst at 433 K. The catalysts were deeply characterized by NH3-TPD, CO2-TPD, BET, XPS and H2-TPR. The characterization results showed that different compositions of catalysts obviously affected the surface properties of the catalysts, but the valence of the metal hardly changed with the Mo/Sn ratios. Raman spectroscopy, XRD and XAFS were further used to characterize the structure of the catalysts. The results indicated that the catalyst composition exerted a significant influence on the structure of MoO3. The formation of oligomeric MoO3 and the appropriate coordination numbers of Mo-O at 1.94 ? are the main reasons for the distinct high catalytic activity of the MoSn catalyst. This journal is
Cu Sub-Nanoparticles on Cu/CeO2 as an Effective Catalyst for Methanol Synthesis from Organic Carbonate by Hydrogenation
Tamura, Masazumi,Kitanaka, Takahisa,Nakagawa, Yoshinao,Tomishige, Keiichi
, p. 376 - 380 (2016)
Cu/CeO2 works as an effective heterogeneous catalyst for hydrogenation of dimethyl carbonate to methanol at 433 K and even at low H2 pressure of 2.5 MPa, and it provided 94% and 98% methanol yield based on the carbonyl and total produced methanol, respectively. This is the first report of high yield synthesis of methanol from DMC by hydrogenation with H2 over heterogeneous catalysts. Characterization of the Cu/CeO2 catalyst demonstrated that reduction of Cu/CeO2 produced Cu metal with 2 surface, which is responsible for the high catalytic performance.
Synergetic Behavior of TiO2-Supported Pd(z)Pt(1-z) Catalysts in the Green Synthesis of Methyl Formate
Baldovino-Medrano, Víctor G.,Pollefeyt, Glenn,Bliznuk, Vitaliy,Van Driessche, Isabel,Gaigneaux, Eric M.,Ruiz, Patricio,Wojcieszak, Robert
, p. 1157 - 1166 (2016)
Methyl formate (MF) is a valuable platform molecule, the industrial production of which is far from being green. In this contribution, TiO2-supported Pd(z)Pt(1-z) catalysts were found to be effective in the green synthesis of methyl formate (MF) - at T=323 K and ambient pressure - through methanol (MeOH) oxidation. Two series of catalysts with similar bulk Pd/(Pd+Pt) molar ratios, z, were prepared; one by a water-in-oil microemulsion (MicE) method and the other by an incipient wetness impregnation (IWI). The MicE method led to more efficient catalysts owing to a weak influence of z on particle size distributions and nanoparticles composition. Pd(z)Pt(1-z)-MicE catalysts exhibited strong synergistic effects for MF production but weak synergistic effects for MeOH conversion. The catalytic performance of Pd(z)Pt(1-z)-MicE was superior to that of Pd(z)Pt(1-z)-IWI catalysts despite the latter displaying synergetic effects during the reaction. The catalytic behavior of TiO2-supported Pd(z)Pt(1-z) catalysts was explained from correlations between XRD, TEM, and X-ray photoelectron spectroscopy characterizations.
The mechanism of dimethyl carbonate synthesis on Cu-exchanged zeolite Y
Zhang, Yihua,Bell, Alexis T.
, p. 153 - 161 (2008)
The mechanism of dimethyl carbonate (DMC) synthesis from oxidative carbonylation of methanol over Cu-exchanged Y zeolite has been investigated using in situ infrared spectroscopy and mass spectrometry under transient-response conditions. The formation of DMC is initiated by reaction of molecularly adsorbed methanol with oxygen to form either mono- or di-methoxide species bound to Cu+ cations. Reaction of the mono-methoxide species with CO produces monomethyl carbonate (MMC) species. DMC is formed via two distinct reaction pathways-CO addition to di-methoxide species or by reaction of methanol with MMC. The rate-limiting step in DMC synthesis is found to be the reaction of CO with mono-methoxide or di-methoxide species. The first of these reactions produces MMC, which then reacts rapidly with methanol to produce DMC, whereas the second of these reactions produces DMC directly. Formaldehyde was identified as an intermediate in the formation of dimethoxy methane (DMM) and methyl formate (MF). Both byproducts are thought to form via a hemiacetal intermediate produced by the reaction of methanol with adsorbed formaldehyde at a Cu+ site.
Study of thermolysis of peroxyacetals and peroxycetals
Helgorsky,Saux,Degueil-Castaing,Maillard
, p. 8263 - 8274 (1996)
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Structural and reactive relevance of V + Nb coverage on alumina of V{single bond}Nb{single bond}O/Al2O3 catalytic systems
Lewandowska, Anna E.,Banares, Miguel A.,Ziolek, Maria,Khabibulin, Dzhalil F.,Lapina, Olga B.
, p. 94 - 103 (2008)
Vanadium and niobium species (together and separately) were loaded on gamma alumina, and the resulting catalysts were run in the methanol conversion. This reaction was studied by both GC analysis and FTIR study in the flow system. The catalytic properties are discussed based on the combined FTIR and 27Al, 51V and 1H MAS NMR studies. The NMR studies revealed a different mechanism of interaction between Nb and Al2O3 than that between V and Al2O3. This predetermines the structure of vanadium sites in bimetallic VNb/Al samples. The effect of coverage was considered for various metal loadings ranging from below to above monolayer. One of our most interesting findings is that the surface Nb oxide species exhibited a redox character below monolayer but were acidic above monolayer. 27Al MAS NMR revealed a strong alumina-Nb interaction that may account for its redox performance. Moreover, the role of sulfate from vanadium precursor is evidenced.
The new catalytic property of supported rhenium oxides for selective oxidation of methanol to methylal
Yuan, Youzhu,Shido, Takafumi,Iwasawa, Yasuhiro
, p. 1421 - 1422 (2000)
A new catalytic property of supported rhenium oxides has been found for selective methanol oxidation to methylal; high performances for the selective catalytic oxidation are observed with V2O5-, ZrO2-, Fe2O3- and TiO2-supported Reoxide catalysts, which are characterized by pulse experiments, XRD and XPS.
Novel anion exchange resin-based catalyst for liquid-phase methanol synthesis at 373-393 K
Aika, Ken-Ichi,Kobayashi, Hidenobu,Harada, Kenji,Inazu, Koji
, p. 1252 - 1253 (2004)
A thermo-stable anion exchange resin-Raney Cu system was found as the most effective solid catalyst for low-temperature liquid-phase methanol synthesis at 373 to 393 K under 5.0 MPa of syngas (2H2/CO). With the catalyst (20 mL of the resin and 2.0 g of Cu) suspended in methanol solution 72% of CO was converted to methanol (70%) and methyl formate (HCOOCH3) (30%) in 4 h.
Vapor-phase dehydrogenation of methanol to methyl formate in catalytic membrane reactor with Pd/SiO2/ceramic composite membrane
Guo, Yanglong,Lu, Guanzhong,Mo, Xunhua,Wang, Yunsong
, p. 1628 - 1629 (2004)
Vapor-phase dehydrogenation of methanol to methyl formate was investigated in the catalytic membrane reactor (CMR) with the Pd/SiO2/ceramic composite membrane prepared by an impregnation method. The studies show that the CMR has much better performance than the fixed-bed reactor, in which no methyl formate is detected under the similar reaction conditions. Copyright
Zirconia-supported MoOx catalysts for the selective oxidation of dimethyl ether to formaldehyde: Structure, redox properties, and reaction pathways
Liu, Haichao,Cheung, Patricia,Iglesia, Enrique
, p. 4118 - 4127 (2003)
Dimethyl ether (DME) reacts to form formaldehyde with high selectivity at 500-600 K on MoOx-ZrO2 catalysts with a wide range of MoOx surface density (0.5-50.1 Mo/nm2) and local structure (monomers, oligomers, MoO3 crystallites, and ZrMo2O8). Reaction rates (per Mo-atom) increased markedly as MoOx surface density increased from 2.2 to 6.4 Mo/nm2 and two-dimensional polymolybdates and MoO3 clusters became the prevalent active species. The rate of incipient stoichiometric reduction of MoOx-ZrO2 samples in H2 also increased with increasing MoOx surface density, suggesting that catalytic turnovers involve redox cycles that become faster as the size and dimensionality of MoOx domains increase. DME reaction rates (per Mo-atom) decreased as MoOx surface densities increased above 6.4 Mo/nm2, as MoO3 and ZrMo2O8 clusters with increasingly inaccessible MoOx species form. On MoOx and ZrMo2O8, areal reaction rates reach a constant value at MoOx surface densities above 10 Mo/nm2, as the exposed surfaces become covered with the respective active species. ZrMo2O8 surfaces were more reducible in H2 than MoOx surfaces and showed higher areal reaction rates. Reaction rates were nearly independent of O2 pressure, but the reaction order in DME decreased from one at low pressures (60 kPa). DME reacts via primary pathways leading to HCHO, methyl formate, and COx, with rate constants k1, k2, and k3, respectively, and via secondary HCHO conversion to methylformate (k4) and COx (k5). Primary HCHO selectivities (and k1/(k2 + k3) ratios) increased with increasing MoOx surface density on MoOx-containing samples and reached values of 80-90% above 10 Mo/nm2. Kinetic ratios relevant to secondary HCHO reactions (k1/[(k4 + k5)CAO]; CAO inlet DME concentration) also increased with increasing MoOx surface density to values of a??0.1 and 0.8 on MoOx and ZrMo2O8 structures (at the constant inlet DME concentration CAO), respectively. Thus, increasing the coverage of ZrO2 surfaces with MoOx or ZrMo2O8 leads to more selective structures for HCHO synthesis from DME.
Ozone-activated nanoporous gold: A stable and storable material for catalytic oxidation
Personick, Michelle L.,Zugic, Branko,Biener, Monika M.,Biener, Juergen,Madix, Robert J.,Friend, Cynthia M.
, p. 4237 - 4241 (2015)
We report a new method for facile and reproducible activation of nanoporous gold (npAu) materials of different forms for the catalytic selective partial oxidation of alcohols under ambient pressure, steady flow conditions. This method, based on the surface cleaning of npAu ingots with ozone to remove carbon documented in ultrahigh vacuum conditions, produces active npAu catalysts from ingots, foils, and shells by flowing an ozone/dioxygen mixture over the catalyst at 150 °C, followed by a temperature ramp from 50 to 150 °C in a flowing stream of 10% methanol and 20% oxygen. With this treatment, all three materials (ingots, foils, and shells) can be reproducibly activated, despite potential carbonaceous poisons resulting from their synthesis, and are highly active for the selective oxidation of primary alcohols over prolonged periods of time. The npAu materials activated in this manner exhibit catalytic behavior substantially different from those activated under different conditions previously reported. Once activated in this manner, they can be stored and easily reactivated by flow of reactant gases at 150 °C for a few hours. They possess improved selectivity for the coupling of higher alcohols, such as 1-butanol, and are not active for carbon monoxide oxidation. This ozone-treated npAu is a functionally new catalytic material.
Levulinic esters from the acid-catalysed reactions of sugars and alcohols as part of a bio-refinery
Hu, Xun,Li, Chun-Zhu
, p. 1676 - 1679 (2011)
Polymeric humin formation greatly diminishes levulinic acid yields in acid treatment of C6 sugars in aqueous medium. Protecting reactive functional groups of sugars and reaction intermediates via acetalisation and etherification in methanol medium effectively suppresses humin formation and remarkably enhances the production of levulinic esters.
ANIONIC GROUP 6B METAL CARBONYLS AS HOMOGENEOUS CATALYSTS FOR CARBON DIOXIDE/HYDROGEN ACTIVATION. THE PRODUCTION OF ALKYL FORMATES.
Darensbourg,Ovalles
, p. 3750 - 3754 (1984)
The production of alkyl formates from the hydrocondensation of carbon dioxide in alcohols utilizing anionic group 6B carbonyl hydrides as catalysts is reported. HM(CO)//5** minus (M equals Cr, W; derived from mu -H left bracket M//2(CO)//1//0 right bracket ** minus ) and their products of carbon dioxide insertion, HCO//2M(CO)//5** minus , have been found to be effective catalysts for the hydrogenation of CO//2 in alcohols under rather mild conditions (loading pressures of CO//2 and H//2, 250 psi each, and 125 degree C) to provide alkyl formates. The only metal carbonyl species detected in solution via infrared spectroscopy, both at the end of a catalytic period and during catalysis, were M(CO)//6 and HCO//2M(CO)//5** minus .
Photocatalytic cross-coupling of methanol and formaldehyde on a rutile TiO2(110) surface
Yuan, Qing,Wu, Zongfang,Jin, Yuekang,Xu, Lingshun,Xiong, Feng,Ma, Yunsheng,Huang, Weixin
, p. 5212 - 5219 (2013)
The photocatalytic oxidation of methanol on a rutile TiO2(110) surface was studied by means of thermal desorption spectroscopy (TDS) and X-ray photoelectron spectroscopy (XPS). The combined TDS and XPS results unambiguously identify methyl formate as the product in addition to formaldehyde. By monitoring the evolution of various surface species during the photocatalytic oxidation of methanol on TiO2(110), XPS results give direct spectroscopic evidence for the formation of methyl formate as the product of photocatalytic cross-coupling of chemisorbed formaldehyde with chemisorbed methoxy species and clearly demonstrate that the photocatalytic dissociation of chemisorbed methanol to methoxy species occurs and contributes to the photocatalytic oxidation of methanol. These results not only greatly broaden and deepen the fundamental understanding of photochemistry of methanol on the TiO2 surface but also demonstrate a novel green and benign photocatalytic route for the synthesis of esters directly from alcohols or from alcohols and aldehydes.
A comparative study on the effect of Zn addition to Cu/Ce and Cu/Ce-Al catalysts in the steam reforming of methanol
Mrad, Mary,Hammoud, Dima,Gennequin, Cédric,Abouka?s, Antoine,Abi-Aad, Edmond
, p. 84 - 90 (2014)
The performances of different catalysts xCu10Ce and xCu10Ce10Al (with x = 1, 3 and 5) in the steam reforming of methanol reaction were studied with and without the presence of zinc. The reaction was investigated at 350°C with a Gas Hourly Space Velocity o
The direct synthesis of dimethyl carbonate by the oxicarbonylation of methanol over Cu supported on carbon nanotube
Merza,László,Oszkó,Pótári,Baán,Erdohelyi
, p. 117 - 124 (2014)
The activity of Cu/MWCNT and Cu-Ni/MWCNT catalysts was investigated in the synthesis of dimethyl carbonate (DMC) by oxidative carbonylation of methanol. The catalysts were prepared via conventional incipient wetness impregnation technique. The samples were characterized by X-ray photoelectron spectroscopy (XPS), and DRIFT. The reaction was carried out in a continuous flow system at atmospheric pressure at 393 K. The main products were methyl formate (MF), DMC and CO2. The methanol conversion on Cu/MWCNT achieved a steady state value after 2 h, but on Cu-Ni/MWCNT the conversion decreased continuously. The DMC selectivity was more than 30% and the yield was 1.2% on Cu/MWCNT. Based on the XPS data we can establish that copper reduced to its metallic form during reduction but oxidized in the reaction mixture, and is mostly in the Cu + state, with some Cu2+ also present on the surface at the beginning of the reaction though its ratio decreased in time. We assume that the DMC formation rate depends on the surface concentration of oxidized Cu. Based upon the FTIR data adsorbed DMC is present on the surface of the Cu/MWCNT catalyst during the catalytic reaction but on Cu-Ni/MWCNT sample only methyl formate was detected in the gas phase.
Low-temperature CO2 hydrogenation to liquid products via a heterogeneous cascade catalytic system
Chen, Yuan,Choi, Saemin,Thompson, Levi T.
, p. 1717 - 1725 (2015)
Research described in this paper targeted a cascade system for the hydrogenation of CO2 to methanol via formic acid and/or formate intermediates, a reaction sequence that has been accomplished previously using homogeneous catalysts. On the basis of results for the hydrogenation of CO2, formic acid, and ethyl formate over a series of Cu- and Mo2C-based catalysts, we selected a Cu chromite catalyst for CO2 hydrogenation to the formate and a Cu/Mo2C catalyst to convert the formate to methanol. These catalysts worked cooperatively in the presence of ethanol, yielding a methanol turnover frequency of 4.7 × 10-4 s-1 at 135 °C, 10 bar of CO2, and 30 bar of H2 in 1,4-dioxane. The performance for this Cu chromite:Cu/Mo2C cascade system surpassed the additive production of the individual catalysts by 60%. The results also allowed an investigation of the reaction pathways. The hydrogenation of CO2 to formic acid appeared to be the rate-limiting step for most of the catalysts. This is not surprising given the thermodynamics for this reaction. Finally, the hydrogenation of CO2 to dimethyl ether was also demonstrated using a system consisting of the Cu/Mo2C catalyst to produce methanol from CO2 and HZSM-5 to produce dimethyl ether from methanol. The systems described in this paper are, to our knowledge, the first demonstrating cascade CO2 hydrogenation via heterogeneous catalysts.
Hydrogenation of carbon dioxide in the presence of rhodium catalysts
Kolesnichenko,Ezhova,Kremleva,Slivinskii
, p. 2542 - 2545 (2004)
The results of CO2 hydrogenation in the presence of the Wilkinson complexes, viz., RhCl3 and acacRh(CO)2, at room temperature and excess PPh3 are presented. The influence of different ions on the catalytic properties of the Rh complexes was studied. Methanol and methyl formate are formed along with formic acid in the presence of an inorganic salt. Ions that are the most active in the formation of formic acid are the least active in methanol formation.
Promotional effect of potassium salt in low-temperature formate and methanol synthesis from CO/CO2/H2 on copper catalyst
Zhao, Tian-Sheng,Yoneyama, Yoshiharu,Fujimoto, Kaoru,Yamane, Nodyuki,Fujimoto, Kenichiro,Tsubaki, Noritatsu
, p. 734 - 735 (2007)
Alkyl formates can be formed from CO2-containing syngas with C1-C4 alkyl alcohol solvents in the presence of potassium carbonate, which changed to potassium formate as catalyst. The formates can be in situ hydrogenolysized further to produce methanol effectively over manganese oxide or magnesia-supported copper catalysts. These homogeneous and heterogeneous catalysts constitute a novel system for methanol synthesis from CO/CO2/H2 even at 443 K. Copyright
Catalytic oxidation of alcohol via nickel phosphine complexes with pendant amines
Weiss, Charles J.,Das, Parthapratim,Miller, Deanna L.,Helm, Monte L.,Appel, Aaron M.
, p. 2951 - 2958 (2014)
Nickel complexes were prepared with diphosphine ligands that contain pendant amines, and these complexes catalytically oxidize primary and secondary alcohols to their respective aldehydes and ketones. Kinetic and mechanistic studies of these prospective electrocatalysts were performed to understand what influences the catalytic activity. For the oxidation of diphenylmethanol, the catalytic rates were determined to be dependent on the concentration of both the catalyst and the alcohol and independent of the concentration of base and oxidant. The incorporation of pendant amines to the phosphine ligand results in substantial increases in the rate of alcohol oxidation with more electron-donating substituents on the pendant amine exhibiting the fastest rates. (Chemical Equation Presented).
Oxidation of methanol to methyl formate over supported Pd nanoparticles: Insights into the reaction mechanism at low temperature
Wojcieszak,Karelovic,Gaigneaux,Ruiz
, p. 3298 - 3305 (2014)
Pd nanoparticles supported on TiO2 and SiO2 (2 wt.%) were synthesized by the water-in-oil microemulsion method. The materials were characterized by standard physico-chemical methods (XRD, ICP, TEM, BET, XPS) and DRIFT in operando mode and tested in the gas-phase reaction of methanol oxidation. The direct formation of methyl formate (MF) from methanol was observed. Supported palladium catalysts produced methyl formate at low temperature (2 occurred. The DRIFT-operando study confirmed that methanol is adsorbed mainly in two forms, the undissociated gaseous methanol (via H bond) and dissociatively adsorbed methoxy species (CH3O-) on the surface. Methyl formate is formed already at RT with the maximum at about 80 °C. The mechanism of the formation of methyl formate from methanol at low temperature is discussed. the Partner Organisations 2014.
Simplified DEMS set up for electrocatalytic studies of porous PtRu alloys
Ianniello,Schmidt
, p. 83 - 86 (1995)
A simplified experimental apparatus for Differential Electrochemical Mass Spectrometry (DEMS) was constructed having only one turbomolecular pump and a modified gas inlet system. The setup allows the determination of the activity of porous PtRu electrodes for the electro-oxidation of small organic molecules. Various PtRu alloys with defined composition can be electrodeposited onto porous gold substrates. First results on the electrooxidation of methanol in acid solution were presented.
CuO - Activated carbon catalysts for methanol decomposition to hydrogen and carbon monoxide
Tsoncheva, Tanya,Nickolov, Radostin,Vankova, Svetoslava,Mehandjiev, Dimitar
, p. 1096 - 1100 (2003)
A comparison of the abilities of CuO - activated carbon catalysts, prepared by different copper precursors and preparation techniques, in the methanol decomposition reaction to carbon monoxide and hydrogen, was undertaken. Higher catalytic activity and stability are found for the catalysts obtained from an ammonia solution of copper carbonate. The nature of the catalytic active complex in the samples is also discussed.
Selective oxidation of methanol to methyl formate on catalysts of Au-Ag alloy nanoparticles supported on titania under UV irradiation
Han, Chenhui,Yang, Xuzhuang,Gao, Guanjun,Wang, Jie,Lu, Huailiang,Liu, Jie,Tong, Min,Liang, Xiaoyuan
, p. 3603 - 3615 (2014)
We find that the Au-Ag alloy nanoparticles supported on titania exhibit superior methanol conversion and methyl formate selectivity for selective oxidation of methanol by low partial pressure oxygen in air under UV irradiation in the 15°C-45°C temperature range, with the highest methanol conversion above 90% and the highest selectivity towards methyl formate above 85%. The only by-product definitely detected is CO2. The superior photocatalytic performance of the catalyst is closely related to the special structure of the catalyst and the electronic properties of the alloy, which reduce the recombination of the photo-excited electron-hole pairs by transferring the photo-excited electrons in time from the conduction band of titania to the alloy on the one hand, and elevate the negative charge level of the alloy surface by the spd hybridization, the formation of Schottky barriers, the electron transfer from the conduction band of titania to the metal as well as the interband and intraband electron transitions under UV irradiation on the other hand. The photo-generated holes are responsible for the oxidation from methanol to coordinated methoxy, from coordinated methoxy to coordinated formaldehyde and finally to carbon dioxide. The methyl formate selectivity is dependent on the density of the surface methoxy. To enhance the efficiency of electron-hole separation is beneficial to the formation of the coordinated methoxy and coordinated formaldehyde and thus the selectivity to methyl formate. The negative charges on the surface of the metal are responsible for the dissociation of oxygen, which is the rate-determining step in the reaction. The dissociative oxygen repels the water molecules formed from the surface hydroxyls and refills the oxygen vacancies on the surface of titania. The surface oxygen is the acceptor of the hydrogen dissociated from methanol and/or methoxy and thus is beneficial for the formation of the coordinated methoxy and coordinated formaldehyde. The oxygen partial pressure remarkably influences the methanol conversion and the methyl formate selectivity. The light intensity has a remarkable impact on the methanol conversion but not on the methyl formate selectivity. These findings provide useful insight into the design of catalysts for selective oxidation of methanol to methyl formate in a more green way. This journal is the Partner Organisations 2014.
RuO2 clusters within LTA zeolite cages: Consequences of encapsulation on catalytic reactivity and selectivity
Zhan, Bi-Zeng,Iglesia, Enrique
, p. 3697 - 3700 (2007)
(Figure Presented) Trapped! The title system (ca. 1 nm diameter; left) catalyzes methanol oxidation with higher turnover rates than clusters on SiO2 supports. Spatial constraints lead to the preferential oxidation of methanol over larger alcohols. Restricted access to active sites also protects encapsulated Ru clusters (right) against inhibition of ethene hydrogenation by organosulfur compounds.
CATALYSTS FOR SELECTIVE OXIDATION OF METHANOL TO DIMETHOXYMETHANE AND RELATED METHODS
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Paragraph 0074-0078, (2021/10/02)
Embodiments include catalyst compositions and methods of synthesizing catalyst compositions for the selective oxidation of methanol to dimethoxymethane, as well as methods of selective oxidation of methanol to dimethoxymethane using catalyst compositions. The catalyst composition can comprise vanadium oxide and a mixed metal oxide, wherein the vanadium oxide is supported on the mixed metal oxide and wherein the mixed metal oxide includes a redox component and an acid component. The method of selective oxidation of methanol to dimethoxymethane can comprise at least the following step: contacting methanol with a catalyst composition in the presence of an oxidizing agent to produce dimethoxymethane.
Preparation of MIL-88B(Fex,Co1?x) catalysts and their application in one-step liquid-phase methanol oxidation to methyl formate using H2O2
Cao, Qiyan,Ji, Shengfu,Liu, Jianfang,Ran, Zhenzhen
, p. 2254 - 2264 (2021/09/20)
The selective oxidation of methanol to methyl formate is one of the most attractive processes to obtain value-added methanol-downstream products. The development of highly efficient and stable catalysts is critical for this transformation. In this study, a series of MIL-88B(Fex,Co1–x) bimetallic catalysts with different Fe/Co molar ratios were prepared through a one-pot hydrothermal method. X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, N2 adsorption-desorption, and inductively coupled plasma-mass spectrometry characterization were performed to elucidate the structure of the catalysts. The activity of the catalysts were assessed in the one-step oxidation of methanol to methyl formate with H2O2 in a liquid-phase batch reactor. The results show that the MIL-88B(Fex,Co1–x) catalysts exhibit uniform needle-like morphologies with an average length and width of 400–600 nm and 100–150 nm, respectively. Co2+ is incorporated into the framework by partially replacing Fe3+ in MIL-88B. Moreover, the catalyst efficiently promoted the conversion of methanol to methyl formate. When MIL-88B(Fe0.7,Co0.3) catalyst was used with a molar ratio of H2O2 to methanol of 0.5 at 80 °C for 60 min, 34.8% methanol conversion was achieved, and the selectivity toward methyl formate was 67.6%. The catalysts also showed great stability with a steady conversion and selectivity even after four cycles. The preliminary oxidation mechanism was also studied. It was determined that H2O2 is first adsorbed on the Fe3+ sites and subsequently activates these sites. Methanol is adsorbed by the O atoms of the framework through hydrogen bonding and is gradually oxidized to formic acid. Subsequently, formic acid reacts with the residual methanol at the Fe3+ and Co2+ Lewis acid sites to form methyl formate.