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.
NHC-CDI Betaine Adducts and Their Cationic Derivatives as Catalyst Precursors for Dichloromethane Valorization
Sánchez-Roa, David,Mosquera, Marta E. G.,Cámpora, Juan
, p. 16725 - 16735 (2021/11/18)
Zwitterionic adducts of N-heterocyclic carbene and carbodiimide (NHC-CDI) are an emerging class of organic compounds with promising properties for applications in various fields. Herein, we report the use of the ICyCDI(p-Tol) betaine adduct (1a) and its cationic derivatives2aand3aas catalyst precursors for the dichloromethane valorization via transformation into high added value products CH2Z2(Z = OR, SR or NR2). This process implies selective chloride substitution of dichloromethane by a range of nucleophiles Na+Z-(preformed or generatedin situfrom HZ and an inorganic base) to yield formaldehyde-derived acetals, dithioacetals, or aminals with full selectivity. The reactions are conducted in a multigram-scale under very mild conditions, using dichloromethane both as a reagent and solvent, and very low catalyst loading (0.01 mol %). The CH2Z2derivatives were isolated in quantitative yields after filtration and evaporation, which facilitates recycling the dichloromethane excess. Mechanistic studies for the synthesis of methylal CH2(OMe)2rule out organocatalysis as being responsible for the CH2transfer, and a phase-transfer catalysis mechanism is proposed instead. Furthermore, we observed that1aand2areact with NaOMe to form unusual isoureate ethers, which are the actual phase-transfer catalysts, with a strong preference for sodium over other alkali metal nucleophiles.
Reaction Network Analysis of the Ruthenium-Catalyzed Reduction of Carbon Dioxide to Dimethoxymethane
Leopold, Max,Siebert, Max,Siegle, Alexander F.,Trapp, Oliver
, p. 2807 - 2814 (2021/05/27)
Due to the growing interest in dimethoxymethane (DMM) as formaldehyde synthon and fuel additive, new and more efficient routes toward the formaldehyde analog are being investigated. One approach is the reductive transformation of carbon dioxide using a ruthenium phosphine catalyst and a Lewis acid additive in methanol. In the present work, we investigated the underlying reaction network, consisting of several intermediates, equilibria and side products, through in situ IR spectroscopy. We determined rate constants and activation parameters for the hydrogenation steps. Their temperature-dependent differences can be used to influence the product selectivity in this catalysis. To favor DMM formation, the acetalization equilibrium and especially the amount of water formed were identified as promising optimization opportunities. Simulation of concentration profiles on the basis of the proposed kinetic model enables the prediction of experimental product distributions for various reaction parameters, demonstrating the power of reaction network analysis for process optimization.