109-87-5Relevant articles and documents
Huang,Lee
, p. 711 (1963)
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Ghysels
, (1924)
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Niobium-substituted octahedral molecular sieve (OMS-2) materials in selective oxidation of methanol to dimethoxymethane
Wasalathanthri, Niluka D.,Guild, Curtis,Nizami, Quddus A.,Dissanayake, Shanka L.,He, Junkai,Kerns, Peter,Fee, Jared,Achola, Laura,Rathnayake, Dinithi,Weerakkody, Chandima,Suib, Steven L.,Nandi, Partha
, p. 32665 - 32673 (2019)
Octahedral molecular sieve (OMS-2) refers to a one-dimensional 2 × 2 framework of octahedral manganese oxo units based on the cryptomelane-type framework. Herein, we describe a niobium (Nb) substituted mixed metal oxide of Nb and Mn where the cryptomelane-type framework is retained. These materials are hydrothermally synthesized from the reaction of potassium permanganate, manganese sulfate, and homogeneous niobium(v) precursors. Niobium incorporation up to 31 mol% can be achieved without destroying the one dimensional 2 × 2 framework. The yields of the materials vary between 70 and 90%. These materials are analyzed by powder XRD, BET isotherm, TEM, SEM, XRF, and XPS studies. The synthesized materials show promising activity in selective oxidation of methanol to dimethoxymethane (DMM) at 200 °C. Normalized activity correlations followed the trend 21% Nb-OMS-2 > 15% Nb-OMS-2 > 31% Nb-OMS-2 > 68% Nb-OMS-2 > K-OMS-2. A fluctuation in methanol conversion was observed around 125-150 °C in most samples, suggesting this to be a catalytically important temperature regime when forming active sites for DMM production.
Synthesis of propylene from renewable allyl alcohol by photocatalytic transfer hydrogenolysis
Caner, Joaquim,Liu, Zijun,Takada, Yuki,Kudo, Akihiko,Naka, Hiroshi,Saito, Susumu
, p. 4093 - 4098 (2014)
Photochemical transformation of biomass-derived or renewable substances with promising scalability is an important challenge for promoting green and sustainable chemistry. We report here that photocatalytic transfer hydrogenolysis of allyl alcohol (obtained from glycerol) gives potentially sustainable propylene with high chemo- and redox selectivity, promoted by powdered Pd/TiO2 in CH3OH (obtained from CO2) under near-ultraviolet-visible light irradiation (λ > 365 nm) at ambient temperature.
A Composite Fe–V/g-C3N4 for Liquid-Phase Selective Oxidation of Methanol with O2 Oxidant
Zhang, Jing,Wang, Hongxia,Lu, Bin,Zhao, Jingxiang,Cai, Qinghai
, p. 909 - 919 (2021)
Abstract: A composite material Fe–V/g-C3N4 prepared by impregnation achieved an efficient performance for heterogeneously catalytic oxidation of methanol to dimethoxymethane (DMM) and poly(oxymethylene) dimethyl ethers (POM) by O2 oxidant in batch reactor, exhibiting 34.3% conversion and > 99.0% selectivity to DMM and POM. However, a pioneered strategy for tuneable synthesis of DMM and POM was realized by controlling the reaction time. The experimental results revealed that FeVO4 and V2O5 nanoparticle crystallizes served as the active sites and higher specific areas 29.3–51.9 m3/g for the catalysts were jointly responsible for the high activity. Besides, the catalyst could be easily recovered and effectively reused. Graphic Abstract: A composite material Fe–V/g-C3N4 with higher specific area exhibited efficient performance for heterogeneously catalytic oxidation of methanol to dimethoxymethane (DMM) and polyoxymethylene dimethyl ether (POM) in batch reactor using O2 oxidant. Moreover, a pioneered strategy for tunable synthesis of DMM and POM was realized by controlling the reaction time. The catalyst was easily recovered and had excellent recycle lifetime and stability. [Figure not available: see fulltext.]
Highly selective oxidation of methanol to dimethoxymethane over SO42-/V2O5-ZrO2
Tao, Meng,Wang, Hongxia,Lu, Bin,Zhao, Jingxiang,Cai, Qinghai
, p. 8370 - 8376 (2017)
The sulfated vanadia-zirconia SO42-/V2O5-ZrO2 catalyst, prepared by an impregnation method and calcined at various temperatures, was found to have a high catalytic activity for methanol oxidation to dimethoxymethane in a fixed bed reactor and a batch autoclave using O2 as the oxidant due to the crystalline V2O5 dispersed on the surface as redox active sites, as well as stronger acidic sites.
Initial Carbon–Carbon Bond Formation during the Early Stages of the Methanol-to-Olefin Process Proven by Zeolite-Trapped Acetate and Methyl Acetate
Chowdhury, Abhishek Dutta,Houben, Klaartje,Whiting, Gareth T.,Mokhtar, Mohamed,Asiri, Abdullah M.,Al-Thabaiti, Shaeel A.,Basahel, Suliman N.,Baldus, Marc,Weckhuysen, Bert M.
, p. 15840 - 15845 (2016)
Methanol-to-olefin (MTO) catalysis is a very active field of research because there is a wide variety of sometimes conflicting mechanistic proposals. An example is the ongoing discussion on the initial C?C bond formation from methanol during the induction period of the MTO process. By employing a combination of solid-state NMR spectroscopy with UV/Vis diffuse reflectance spectroscopy and mass spectrometry on an active H-SAPO-34 catalyst, we provide spectroscopic evidence for the formation of surface acetate and methyl acetate, as well as dimethoxymethane during the MTO process. As a consequence, new insights in the formation of the first C?C bond are provided, suggesting a direct mechanism may be operative, at least in the early stages of the MTO reaction.
Unsensitized photooxidation of sulfur compounds with molecular oxygen in solution
Robert-Banchereau, Evelyne,Lacombe, Sylvie,Ollivier, Jean
, p. 2087 - 2102 (1997)
The short wavelength irradiation of aliphatic disulfides, sulfides and of n-butanethiol in alcohols or aqueous acetonitrile in the presence of oxygen was investigated: the corresponding sulfonic acids are produced in good yields for short alkyl chain compounds, together with smaller amounts of sulfuric and carboxylic acids. In acetonitrile, the influence of added water on the reaction course is evidenced: increased reaction rate and acid yields, control of sulfuric acid formation. Intermediates such as sulfinic acid and thiosulfonate were detected and their rates of formation were monitored. The reaction appears to involve thiyl radicals giving rise to sulfonyl radicals in the presence of oxygen. A first tentative hypothesis concerning the mechanism is advanced.
Poly(4-vinylpyridine) catalyzed selective methanolysis of methyl and methylene bromides
Prakash, G.K. Surya,Colmenares, Juan C.,Batamack, Patrice T.,Mathew, Thomas,Olah, George A.
, p. 6016 - 6018 (2009)
The effect of poly(4-vinylpyridine) (PVP) on the methanolysis of methyl bromide and methylene bromide was studied at temperatures between 75 °C and 125 °C. PVP acts as an efficient HBr scavenger promoting the formation of dimethyl ether (DME) and dimethox
Rasuwaew et al.
, p. 495,498;engl.Ausg.S.463 (1955)
Site Titration with Organic Bases During Catalysis: Selectivity Modifier and Structural Probe in Methanol Oxidation on Keggin Clusters
Liu, Haichao,Bayat, Nader,Iglesia, Enrique
, p. 5072 - 5075 (2003)
The selective and permanent titration of protons with organic bases (2,6-di-tertbutylpyridine or pyridine) provides an accurate measure of the dispersion of Keggin structures during catalytic oxidation of methanol. Titration allows the systematic control of the redox and acid properties of H3+nPVnMo12-nO40 (n=0-4) Keggin clusters and leads to unprecedented selectivity in the formation of dimethoxymethane (>80%) and high yields.
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Price,Krishnamurti
, p. 5335 (1950)
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VOx molecular level grafted g-C3N4 for highly selective oxidation of methanol to dimethoxymethane
Ma, Hongrui,Wang, Hongxia,Lu, Bin,Zhao, Jingxiang,Cai, Qinghai
, p. 48 - 56 (2019)
A composite material VOx/g-C3N4 was prepared and its composition and structure was characterized by FT-IR, XRD, SEM, TEM and XPS. The results showed that VOx was grafted on g-C3N4 surface with molecularlevel dispersion via V or O atoms interacting with the characteristic groups on g-C3N4 surface. The highly dispersed VOx/g-C3N4 exhibited effectively catalytic activity and high selectivity for oxidation of methanol into methoxymethane (DMM), giving 44.9 mol/(molV·h) TOF and 95.2% selectivity of DMM. The dependence of catalytic activity on the surface properties and preparation procedure of the catalyst, reaction conditions and kinetics, and the stability of the catalyst were explored. Also, the in situ DRIFTS spectra of methanol adsorption on the VOx/g-C3N4 surface and effect of O2 on the adsorption, as well as the reaction mechanism were discussed.
Sonochemical synthesis of vanadium complex nano-particles: a new precursor for preparation and evaluation of V2O5/Al2O3 nano-catalyst in selective oxidation of methanol to methylal
Jamei, Mohammad Reza,Ranjbar, Maryam,Eliassi, Ali
, p. 2627 - 2635 (2017)
In this study, an ionic complex of V(V) was synthesized by using ultrasonic method, and it was used as a precursor for production of a new catalyst for selective preparation of methylal or dimethoxymethane (DMM). By reaction between an ionic ligand [pyda.H2]2+[pydc]2? (LH2), (pyda.H2?=?2,6-pyridine diammonium and pydc?=?2,6-pyridinedicarboxylate) and ammonium vanadate, the five coordinated V(V) complex, [pyda.H][V(pydc)O2], {2,6- diaminopyridinum 2,6-pyridinedicarboxylatodioxovanadate(V)}, VLH2 was synthesized. The prepared complex VLH2 was characterized by SEM, thermal analysis TGA/DTA, FT-IR spectroscopy and X-ray diffraction studies. The results showed that the yield of the reaction was increased up to 64%. The average particle sizes of the obtained complex VLH2 were about 50–60?nm. Also, the nano-catalyst of V2O5/Al2O3 was synthesized by impregnation method and was prepared as a nano-catalyst with average particles sizes of 50–60?nm, and its characterization was performed by XRD, EDX and SEM methods. Finally, the prepared catalyst was used to converting of methanol to methylal at different process conditions.
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.
Reaction Mechanism of Pd-Catalyzed “CO-Free” Carbonylation Reaction Uncovered by In Situ Spectroscopy: The Formyl Mechanism
Geitner, Robert,Gurinov, Andrei,Huang, Tianbai,Kupfer, Stephan,Gr?fe, Stefanie,Weckhuysen, Bert M.
supporting information, p. 3422 - 3427 (2020/12/15)
“CO-free” carbonylation reactions, where synthesis gas (CO/H2) is substituted by C1 surrogate molecules like formaldehyde or formic acid, have received widespread attention in homogeneous catalysis lately. Although a broad range of organics is available via this method, still relatively little is known about the precise reaction mechanism. In this work, we used in situ nuclear magnetic resonance (NMR) spectroscopy to unravel the mechanism of the alkoxycarbonylation of alkenes using different surrogate molecules. In contrast to previous hypotheses no carbon monoxide could be found during the reaction. Instead the reaction proceeds via the C?H activation of in situ generated methyl formate. On the basis of quantitative NMR experiments, a kinetic model involving all major intermediates is built which enables the knowledge-driven optimization of the reaction. Finally, a new reaction mechanism is proposed on the basis of in situ observed Pd-hydride, Pd-formyl and Pd-acyl species.
