Hydrogenation of Alkenes on Molybdenum and Tungsten Carbides

Akopyan, A. V.; Polikarpova, P. D.; Forofontova, O. I.; Левин, И. С.; Mnatsakanyan, R. A.; Davtyan, Davit; Zurnachyan, A. R.; Анисимов, А. В.; Караханов, Э. А.

doi:10.1134/s0040579520050036

Cited by 2 publications

(3 citation statements)

References 20 publications

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“…Pure tungsten oxide (WO 3 ) and carbon powder (Vulcan XC-72R, Cabot Co) were used as the precursors for the synthesis of WC. Carbon served as both a precursor for obtaining tungsten carbide 43 and as the thermal reducer because carbon is highly efficient at absorbing microwave energy and converting it into heat. A stoichiometric ratio of the elements in the initial mixture was calculated based on the WO 3 + 4C = WC + 3CO equation.…”

Section: Experimental Sectionmentioning

confidence: 99%

New Type of Catalyst for Efficient Aerobic Oxidative Desulfurization Based On Tungsten Carbide Synthesized by the Microwave Method

et al. 2022

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Herein, we present a new type of high-performance catalyst for aerobic oxidation of organosulfur compounds based on tungsten carbide. The synthesis of tungsten carbide was performed via microwave irradiation of the precursors, which makes it possible to obtain a catalyst in just 15 min. The synthesized catalyst was investigated by a variety of physicochemical methods: X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, electron microscopy, and N 2 adsorption/desorption. It was shown that active centers containing tungsten in the transition oxidation state (+4) play a key role in the activation of oxygen. The main factors influencing the conversion of dibenzothiophene (DBT) were investigated. It should be noted that 100% conversion of DBT can be achieved under relatively mild conditions: 120 °C, 3 h, 6 bar, and 0.5% wt catalyst. The catalyst retained its activity for at least six oxidation/regeneration cycles. The simplicity and speed of synthesis of the proposed catalyst in combination with its high activity and stability open broad prospects for its further use both for oxidative desulfurization and for other reactions of aerobic oxidation of organic substrates.

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Section: Experimental Sectionmentioning

confidence: 99%

New Type of Catalyst for Efficient Aerobic Oxidative Desulfurization Based On Tungsten Carbide Synthesized by the Microwave Method

et al. 2022

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“…The corresponding secondary allylic alcohols (1a-10a) were isolated in moderate to good yields (50-74%) by simple chromatographic purification on SiO 2 after the in situ reduction of the corresponding, initially formed hydroperoxides by PPh 3 . To further investigate the generality of our catalytic protocol, Mo-POM was used as an efficient 1 O 2 generator for the oxygenation of cis-1,2-dimethyl-substituted styrenes (11)(12)(13)(14)(15)(16)(17). In all cases, the desired allylic alcohols 11a-17a (after addition of PPh 3 ) were formed in a 9/1 mole ratio with the corresponding tertiary 11b-17b (see Table S6) and were isolated by column chromatography in good yields 63-70% (Scheme 3).…”

Section: Application On the Catalytic Selective Oxygenation Of Alkene...mentioning

confidence: 99%

“…Among the widely used, early-transition-metal catalytic materials, the carbides of the earth-abundant Mo and W (Mo 2 C and W 2 C) [1][2][3] feature catalytic properties similar to those of noble metals [4,5]. Several catalytic processes, including Fischer-Tropsch (FT) synthesis [6,7], methane dry reforming [8], water-gas shift (WGS) reaction [9,10], alkenes [11] and CO/CO 2 hydrogenation into value-added chemicals (methanol, dimethyl ether) or fuels (methane and heavier hydrocarbons), have been reported using these two materials [12][13][14][15][16][17][18]. In particular, Mo 2 C [19] has been reported to be a very effective catalyst for several redox transformations [12,13,[20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Mo2C as Pre-Catalyst for the C-H Allylic Oxygenation of Alkenes and Terpenoids in the Presence of H2O2

et al. 2022

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In this study, commercially available molybdenum carbide (Mo2C) was used, in the presence of H2O2, as an efficient pre-catalyst for the selective C-H allylic oxygenation of several unsaturated molecules into the corresponding allylic alcohols. Under these basic conditions, an air-stable, molybdenum-based polyoxometalate cluster (Mo-POM) was formed in situ, leading to the generation of singlet oxygen (1O2), which is responsible for the oxygenation reactions. X-ray diffraction, SEM/EDX and HRMS analyses support the formation mainly of the Mo6O192− cluster. Following the proposed procedure, a series of cycloalkenes, styrenes, terpenoids and methyl oleate were successfully transformed into hydroperoxides. After subsequent reduction, the corresponding allylic alcohols were produced with good yields and in lab-scale quantities. A mechanistic study excluded a hydrogen atom transfer pathway and supported the twix-selective oxygenation of cycloalkenes on the more sterically hindered side via the 1O2 generation.

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Hydrogenation of Alkenes on Molybdenum and Tungsten Carbides

Cited by 2 publications

References 20 publications

New Type of Catalyst for Efficient Aerobic Oxidative Desulfurization Based On Tungsten Carbide Synthesized by the Microwave Method

New Type of Catalyst for Efficient Aerobic Oxidative Desulfurization Based On Tungsten Carbide Synthesized by the Microwave Method

Mo2C as Pre-Catalyst for the C-H Allylic Oxygenation of Alkenes and Terpenoids in the Presence of H2O2

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