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1.
The gas-phase reaction of diethyl disulfide hydrogenation at atmospheric pressure in the presence of supported transition metal sulfides was studied. The reaction of diethyl disulfide with hydrogen at T = 200°C resulted in ethanethiol, and the selectivity to ethanethiol was no lower than 94%. The selectivity decreased at a higher temperature because of diethyl disulfide decomposition to ethylene and hydrogen sulfide. The reaction of diethyl disulfide in the presence of hydrogen occurred at a higher rate and selectivity than that in an atmosphere of helium. The activity of metal sulfides supported on aluminum oxide was higher than on the other studied supports—aluminosilicate, silica gel, and a carbon support. Metal sulfides supported on Al2O3 were arranged in the following order according to their activity: Rh > Ru > Mo Pd > Ni > W. Bimetallic catalysts were less active than monometallic catalysts. The activity of catalysts increased with the sulfide sulfur content; the partial reduction of metal sulfides also increased the catalytic activity. 相似文献
2.
V. M. Kudenkov L. I. Kiseleva A. V. Mashkina 《Reaction Kinetics and Catalysis Letters》1991,45(2):227-233
Kinetic data show that in the presence of K2WO4/Al2O3, methanethiol is largely produced by the reaction of H2S with metanol and partly with dimethyl ether. Dimethyl sulfide is formed during the interaction of methanethiol with methanol, of H2S with dimethyl ether and as a result of methanethiol disproportionation. Methane and carbon oxides are the decomposition products of methanethiol and dimethyl sulfide and of methanol and dimethyl ether, respectively.
, K2WO4/Al2O3 H2S — . , H2S . , — .相似文献
3.
A. V. Mashkina V. R. Grunvald B. P. Borodin V. I. Nasteka V. N. Yakovleva L. N. Khairulina 《Reaction Kinetics and Catalysis Letters》1991,43(2):361-365
Na+/Al2O3 catalysts in disproportionation of methanethiol are highly selective towards dimethyl sulfide but less active compared to -Al2O3. Their activity falls with increasing Na+ in the sample. This decrease is due to the neutralization of Brönsted acid centers on the catalyst.
Na+/Al2O3 , , -Al2O3. Na+ . .相似文献
4.
A. V. Mashkina V. N. Yakovleva L. G. Sakhaltueva 《Reaction Kinetics and Catalysis Letters》1994,53(2):363-368
We have studied dimethyl disulfide conversion on heterogeneous catalysts in a flow setup at T=250–350°C and atmospheric pressure. Methyl mercaptan appears to be the main reaction product. The rate of dimethyl disulfide decomposition and its selectivity towards methyl mercaptan in H2S medium are higher than those in pure helium. Thus the process seems to involve the surface protons formed upon dissociative H2S chemisorption. 相似文献
5.
A. V. Mashkina V. R. Grunvald V. I. Nasteka B. P. Borodin V. N. Yakovleva L. N. Khairulina 《Reaction Kinetics and Catalysis Letters》1990,41(2):357-362
Disproportionation of thiol to sulfide and H2S takes place on catalysts of various composition, the most active being those with paired acid-base centers. On these catalysts at 200–400°C methanethiol is quantitatively converted to dimethyl sulfide. Disproportionation of ethanethiol and particularly of 2-propanethiol is accompanied by the decomposition of sulfides formed and initial thiols to produce olefins and H2S.
H2S , - . 200–400°C . 2- H2S.相似文献
6.
A. V. Mashkina 《Russian Journal of Applied Chemistry》2011,84(7):1223-1228
Thiophene formation under various conditions from furan and H2S in the presence of γ-Al2O3, both unpromoted and promoted with transition metal oxides, was examined. The conditions enabling preparation of thiophene
in a 95–98 mol% yield were determined. 相似文献
7.
L. A. Dunyushkina E. A. Mashkina I. Yu. Nechaev A. A. Babkina N. O. Esina B. V. Zhuravlev A. K. Demin 《Ionics》2002,8(3-4):293-299
The electrical conductivity of the SrTi1−xFexO3−δ, BaTi1−xFexO3−δ and SrTi1−xMnxO3−δ systems has been studied in a range of oxygen partial pressures between 10−16 and 0.21 atm at 900 and 1000 °C. The materials exhibit predominantly ionic conductivity in a wide range of intermediate oxygen
partial pressures. It has been found that in Fe doped strontium and barium titanates, the dependencies of the ionic conductivity
on the acceptor concentration show a local maximum near x=0.2. Taking into account that in the CaTi1−xFexO3−δ system (x=0−0.5), the concentration dependence of the ionic conductivity also has a maximum near x=0.2, it can be concluded
that this is a common phenomenon for Fe doped alkali earth titanates. An assumption has been made that a scheme of defect
formation devised earlier for Fe doped calcium titanate is applicable for other alkali earth titanates. 相似文献
8.
9.
A. V. Mashkina 《Kinetics and Catalysis》2008,49(6):802-811
The results of the studies of catalytic conversions of lower dialkyl disulfides performed at the Boreskov Institute of Catalysis (Siberian Branch, Russian Academy of Sciences) are summarized. The selective hydrogenolysis of dimethyl and diethyl disulfides with the formation of alkanethiols occurs in a hydrogen medium on transition metal sulfides. Dimethyl disulfide turns into dimethyl sulfide in an inert gas medium on oxide catalysts with acid and basic sites on their surface. Lower dialkyl disulfides are dehydrocyclized to thiophene under the action of sulfide catalysts. In an oxygen medium on the metal oxides and salts, diethyl disulfide and a lower disulfide concentrate are selectively oxidized to form alkanethiolsulfinates, alkanethiolsulfonates, and alkanesulfonic acids. 相似文献
10.
The gas-phase reaction of dimethyl disulfide with thiophene proceeds under the action of acid catalysts under atmospheric pressure at 160–350°C and a residence time of τ = 0.6–21 s to form thioalkylation and alkylation products. Dimethyl disulfide reacts with benzene to form only alkylation products. Catalysts containing both strong protic and Lewis acid sites, as well as basic sites of moderate strength, are the most active ones. 相似文献