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
Surface and catalytic properties of Ce-, Zr-, Au-, Cu-modified SBA-15
Kaminski, Piotr,Ziolek, Maria
, p. 249 - 262 (2014)
Au- and CeO2-containing catalysts, supported on SBA-15 mesoporous molecular sieves and loaded with additives such as Cu and Zr species, were obtained and characterised. Cerium oxides are preferentially located in the bulk of SBA-15, whereas Zr species on its surface. Gold and copper loaded on supports strongly interact resulting in the electron transfer from Cu + to metallic gold, thus enhancing redox properties. Moreover, cerium species interact with gold, increasing redox properties of the system. The presence of copper increases the gold dispersion. Ce- and Zr-containing supports contain Lewis acid sites (LAS). The number of LAS is increased by the modification with copper species, whereas gold loading diminishes the LAS content. The presence of Zr species is responsible for Bronsted acidity and directs the oxidation of methanol to dimethyl ether. Copper enhances the selectivity to methyl formate. Gold and cerium are responsible for total oxidation of methanol, which is enhanced by modification with copper. The most attractive catalyst for low temperature total oxidation of methanol is bimetallic AuCu/CeSBA-15.
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.
VAPOR PHASE CARBONYLATION OF METHYL ACETATE, METHANOL, AND DIMETHYL ETHER WITH MOLYBDENUM-ACTIVE CARBON CATALYST
Shikada, Tsutomu,Yagita, Hiroshi,Fujimoto, Kaoru,Tominaga, Hiro-o
, p. 547 - 550 (1985)
A molybdenum-active carbon catalyst was found to catalyze the vapor phase carbonylation of methyl acetate and related compounds under pressurized conditions in the presence of methyl iodide promoter.Acetic anhydride was formed from methyl acetate with an yield of 15percent and a selectivity of 83percent at 250 deg C and 45 atm.The molybdenum-active carbon catalyst was active also for the carbonylation of methanol and dimethyl ether to form methyl acetate.
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.
Chemical species active for selective oxygenation of methane with hydrogen peroxide catalyzed by vanadium-containing compounds
Seki, Yasuhiro,Mizuno, Noritaka,Misono, Makoto
, p. 1195 - 1196 (1998)
UV-vis data revealed that monoperoxomonovanadate is an active species for liquid-phase oxygenation of methane with hydrogen peroxide catalyzed vanadium-containing catalysts in trifluoroacetic anhydride.
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.
Ester synthesis by NAD(+)-dependent dehydrogenation of hemiacetal: production of methyl formate by cells of methylotrophic yeasts.
Murdanoto,Sakai,Sembiring,Tani,Kato
, p. 1391 - 1393 (1997)
A water-soluble ester, methyl formate, was detected as a metabolite in the culture medium of methylotrophic yeasts. Methyl formate synthase, which catalyses NAD(+)-dependent dehydrogenation of the hemiacetal adduct of methanol and formaldehyde, catalyses the ester synthesis. The enzyme activity was induced on a methanol medium and was increased further by the addition of formaldehyde. In the reaction system using intact cells of Pichia methanolica AKU 4262, 135 mM (8.1 g/liter) methyl formate was produced from 2 M methanol. This is a new biological process for ester synthesis that couples spontaneous formation of hemiacetal and alcohol dehydrogenase.
Redox chemistry of gaseous reactants inside photoexcited FeAlPO4 molecular sieve
Ulagappan,Frei
, p. 490 - 496 (2000)
Photochemical studies were conducted to probe the reactivity of the excited Fe-O ligand-to-metal charge-transfer state of the Fe-substituted aluminophosphate sieve with AFI structure (FeAlPO4-5 or FAPO-5), at the gas-micropore interface. Laser light at 350-430 nm was used to excite the metal centers, and low alcohols (methanol, 2-propanol) and O2 were used as donors and electron acceptor, respectively. Subsequent proton transfer and H atom abstraction yielded formaldehyde (acetone) and H2O2, resulting in an overall two-electron transfer process. In these products, acetone was stable in the sieve, while formaldehyde underwent fast Cannizzaro reaction and H2O2 disproportionated to H2O and O2. O2 was efficiently reduced by transient framework Fe+II, indicating that its reduction potential lies at least 0.50 of a volt more than that of a conduction band of dense-phase Fe2O3 particles, which may make available demanding photoreductions not accessible by photochemistry at iron oxide semiconductors materials.
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.
