排序方式: 共有14条查询结果,搜索用时 31 毫秒
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V. I. Zaikovskii A. V. Vosmerikov V. F. Anufrienko L. L. Korobitsyna E. G. Kodenev G. V. Echevskii N. T. Vasenin S. P. Zhuravkov E. V. Matus Z. R. Ismagilov V. N. Parmon 《Kinetics and Catalysis》2006,47(3):389-394
The MoZSM-5 (4.0 wt % Mo) catalyst has been characterized by high-resolution transmission electron microscopy, EDXA, and EPR. Two types of molybdenum-containing particles are stabilized in the catalyst in the course of nonoxidative methane conversion at 750°C. These are 2-to 10-nm molybdenum carbide particles on the zeolite surface and clusters smaller than 1 nm in zeolite channels. According to EPR data, these clusters contain the oxidized molybdenum form Mo5+. The surface Mo2C particles are deactivated at the early stages of the reaction because of graphite condensation on their surface. Methane is mainly activated on oxidized molybdenum clusters located in the open molecular pores of the zeolite. The catalyst is deactivated after the 420-min-long operation because of coke buildup on the zeolite surface and in the zeolite pores. 相似文献
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Lysenko Elena N. Surzhikov Anatoly P. Nikolaev Evgeniy V. Vlasov Vitaly A. Zhuravkov Sergey P. 《Journal of Thermal Analysis and Calorimetry》2018,134(1):307-312
Journal of Thermal Analysis and Calorimetry - The effect of mechanical milling on the oxidation kinetics of ultrafine iron powders was investigated by thermogravimetric (TG) analysis. The initial... 相似文献
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A. V. Vosmerikov V. I. Zaikovskii L. L. Korobitsyna V. V. Kozlov N. V. Arbuzova S. P. Zhuravkov 《Kinetics and Catalysis》2011,52(3):427-433
Nonoxidative methane conversion into aromatic hydrocarbons over ZSM-5-type high-silica zeolites modified with nanosized powders
of molybdenum (4.0 wt %) and silver (0.1–0.5 wt %) is reported. The acidic properties of the catalysts have been investigated
by temperature-programmed ammonia desorption. The microstructure and composition of the Ag-Mo/ZSM-5 catalytic systems have
been studied by high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy. The doping of the
Mocontaining zeolite with silver enhances its activity and stability in nonoxidative methane conversion into aromatic hydrocarbons. 相似文献
4.
The State of the Active Sites and Deactivation of Mo-ZSM-5 Catalysts of Methane Dehydroaromatization
5.
T. A. Fedushchak T. V. Petrenko A. V. Vosmerikov D. A. Kanashevich S. P. Zhuravkov L. M. Velichkina 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(3):375-379
New hydrofining catalysts based on molybdenum, nickel, and aluminum nitride nanopowders produced by electrical explosion are
obtained. Their physicochemical properties are studied. The direct sulfurizing of molybdenum nanopowders with sulfides from
straight-run diesel oil fraction is shown to be possible. The high hydrodesulfurization capability of nanopowder catalysts
is established. 相似文献
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A. V. Vosmerikov V. I. Zaikovskii L. L. Korobitsyna G. V. Echevskii V. V. Kozlov Ya. E. Barbashin S. P. Zhuravkov 《Kinetics and Catalysis》2009,50(5):725-733
The nonoxidative conversion of methane into aromatic hydrocarbons on high-silica zeolites ZSM-5 containing nanosized powders
of molybdenum (4.0 wt %) and nickel (0.1–2.0 wt %) was studied. Data on the acid characteristics of the catalysts and the
nature and amount of coke deposits formed on the surface of the catalysts were obtained using the thermal desorption of ammonia
and thermal analysis. The microstructure and composition of Ni-Mo/ZSM-5 catalysts were studied by high-resolution transmission
electron microscopy and energy-dispersive X-ray analysis. The formation of various chemical species in the samples was detected:
oxide-like clusters of Mo within zeolite channels (∼1 nm), molybdenum carbide particles (5–30 nm) on the outer surface of
the zeolite, and Ni-Mo alloy particles with different compositions (under reaction conditions, carbon filaments grew on these
particles). It was found that, as the Ni content was increased from 0.1 to 2.0 wt %, the rate of deactivation of the catalytic
system increased because of blocking pores in the zeolite structure by filamentous carbon up to the formation of condensed
coke deposits. 相似文献
8.
A. V. Vosmerikov G. V. Echevskii L. L. Korobitsyna N. V. Arbuzova E. G. Kodenev L. M. Velichkina C. P. Zhuravkov 《Kinetics and Catalysis》2007,48(3):409-413
The effects of the tungsten concentration and of the method of tungsten introduction into ZSM-5 pentails with different SiO2/Al2O3 molar ratios on the acidity and the activity of the resulting catalysis in nonoxidative methane conversion into aromatic hydrocarbons are considered. The catalysts obtained from the SiO2/Al2O3 = 40 pentasil and a nanosized tungsten powder are the most active and the most stable. The maximum methane conversion and the highest yield of aromatic hydrocarbons are achieved on the zeolite containing 8.0 wt % tungsten nanopowder. 相似文献
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