Effect of the paste molding pressure on the activity of iron oxide catalyst in dehydrogenation of methylbutenes

The effect of the paste molding pressure on the activity of an iron oxide catalyst in dehydrogenation of methylbutenes was studied. The study involved detailed analysis of the pore structure of the samples by mercury porosimetry and determination of the mode of the catalytic process (kinetic or diffusion control). The range of pore sizes in which dehydrogenation reactions occur was determined.     

Transformation of the phase structure of an iron oxide catalyst for dehydrogenation of methyl butenes under industrial exploitation conditions

X-ray phase, differential-thermal, and elemental analyses were used to study the transformation of the phase structure of an iron oxide catalyst for dehydrogenation of methyl butenes after exploitation.     

Effect of calcination temperature on the performance of nano-size iron oxide catalysts for ethylbenzene dehydrogenation

The effect of calcination temperature on the physicochemical properties and catalytic performance of nano-sized Fe-K oxides for ethylbenzene dehydrogenation was investigated. The catalyst calcined at 600°C showed the highest activity. The catalytic activity of the catalysts clearly depended on the structure of the nano-sized iron catalysts.     

Advantages of ethane oxidative dehydrogenation on the MoVNbTeOx catalyst under elevated pressure

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Effect of the conditions of preparing mixed oxide catalyst of Mo-V-Te-Nb-O composition on its activity in the oxidative dehydrogenation of ethane

It is shown that catalytic activity of mixed oxide catalyst of Mo-V-Te-Nb-O composition in oxidative dehydrogenation (OD) of ethane is determined to a substantial degree by the Nb-to-(C₂O₄)^2? ratio in niobium-containing precursors. A pH value of 2.8 to 3.0 for a mixture is optimal when conducting the hydrothermal synthesis of a mixed oxide catalyst; this is achieved by using oxaloniobic acid as a niobium-containing precursor. It is determined that substituting antimony for tellurium results in a loss of catalyst activity during the OD of ethane. The optimum Te content in a catalyst is 0.17 mol %.     

Effect of high-temperature treatment on the properties of an alumina-chromium catalyst for the dehydrogenation of lower paraffins

The crystal and pore structures of a microspherical alumina-chromium catalyst calcined at 800–1100°C were studied using a set of currently available physicochemical techniques (X-ray diffraction, lowtemperature nitrogen adsorption, diffuse reflectance UV-vis spectroscopy, Raman spectroscopy, and EPR spectroscopy); the state of its active component and the catalytic properties in isobutane dehydrogenation were examined. As the calcination temperature was increased from 800 to 900–1000°C, the properties of the catalyst were improved as a result of the formation of Cr₂O₃ clusters in an optimum amount and a decrease in the surface acidity of the catalyst due to the dehydroxylation and phase transformations of the aluminum oxide support. Calcination at 1100°C was accompanied by a decrease in the yield of isobutylene as a result of the formation of inactive macrocrystalline chromium (III) oxide and a chromium species inaccessible to reacting molecules; this chromium species was encapsulated in closed pores as the constituent of a solid solution of α-Al₂O₃-Cr₂O₃.     

乙苯氧化脱氢反应Fex/TiO2的催化性能研究

新型氧化钛负载铁催化剂Fex/TiO2在低温乙苯空气氧化脱氢制苯乙烯反应中具有良好的催化活性。350 ℃,使用Fe7/TiO2催化剂,当Fe的质量分数为7%时,可获得14.6%乙苯单程转化率和99.0%的苯乙烯选择性。通过X衍射、表面吸附、热分析及扫描电镜仪器分析表征,考察氧化钛负载铁催化剂在乙苯低温氧化脱氢反应中的催化作用。350 ℃乙苯可被活化,催化剂活性的高低取决于活性物种Fe(III)的分布状态和质量分数。     

Effect of the catalyst structure on the catalytic activity in dehydrogenation of 2-methyl butane

Calorimetry, thermogravimetry, X-ray diffraction analysis, and low-temperature adsorption of nitrogen were used to study the structure of bimetallic Pt—Sn catalysts on zinc–alumina spinel supports. The effect of the porous structure of the catalyst samples synthesized on their catalytic activity in dehydrogenation of 2–methyl butane was analyzed.     

Effect of calcination conditions on the properties of a catalyst for ethylbenzene dehydrogenation

Summary The effects of calcination conditions on the properties of the catalyst for dehydrogenation of ethylbenzene were studied by using TG, DTA, and XRD. The formation temperature of polyferrite was higher than 600°C. The strength of the catalyst changed during calcination. Higher temperature enhanced the strength and improved the activity of catalyst. The calcination model has great influences on the catalyst performance. Multi-stage calcination improved the catalyst activity.     

Hydrogenation of carbon dioxide over iron oxide catalyst

Hydrogenation of carbon dioxide was carried out over reduced Fe₃O₄ catalyst. Effect of reduction temperature of the catalyst, reaction temperature, space velocity, and component of feed gas were examined on the catalyst. From various experiments, the proper conditions for the hydrogenation of carbon dioxide are proposed. In addition, oxidation of the catalyst took place simultaneously during the hydrogenation of CO₂.

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Reduced graphene oxide as a recyclable catalyst for dehydrogenation of hydrazo compounds

Reduced graphene oxide served as a reusable and efficient carbocatalyst for aerobic oxidative dehydrogenation of hydrazo compounds. Azo compounds were obtained in high yields under mild reaction conditions.     

Oxidative dehydrogenation of ethylbenzene with carbon dioxide over zeolite-supported iron oxide catalysts

Oxidative dehydrogenation of ethylbenzene with carbon dioxide was carried out over ZSM-5 zeolite-supported iron oxide catalysts. In the presence of carbon dioxide, ethylbenzene was predominantly converted into styrene by oxidation. It was found that carbon dioxide in this reaction plays a role as a soft oxidant to greatly improve catalytic activity. An active phase for the dehydrogenation with carbon dioxide was suggested as rather reduced and isolated magnetite-like phase having oxygen deficiency in zeolite matrix.     

Effect of reaction products on dehydrogenation rate of isoamylenes on a membrane catalyst

Conclusions The dehydrogenation of isoamylenes on a membrane catalyst composed of a Pd catalyst with 5.9% Ni under nongradient conditions is inhibited by isoprene, while the reaction rate passes through a maximum when the partial pressure of hydrogen in the starting mixture is increased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2602–2603, November, 1976.