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1.
The activation of adsorbed CO is an important of first step in the hydrogenation of CO to form hydrocarbons and alcohols. This paper focuses on the roles of metal composition, attack on the adsorbed CO by adsorbed hydrogen, and metal oxide additives. Results from both theoretical and experimental studies are presented.  相似文献   

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预处理Fe基催化剂CO加氢合成低碳烯烃选择性影响研究   总被引:1,自引:0,他引:1  
研究了Fe2O3在CO和H2气氛下预处理对催化剂物相、表面组成和性质的影响及CO加氢合成低碳烯烃反应行为。结果表明,300℃ H2预处理后催化剂主要物相结构为Fe3O4和α-Fe,250℃ CO预处理后主要物相为Fe3O4,随着CO预处理温度的升高,有碳化铁生成。表面碳化物含量随着CO预处理温度的升高而增加。CO较H2预处理表面碱性增强,CO2和CO吸附显著增加,随着预处理时间的延长,表面积炭降低了CO2和CO吸附。经CO预处理的催化剂具有较高的烯烃选择性,H2预处理的催化剂烯烃选择性相对较低。  相似文献   

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Conversion of CO2 into chemicals is a promising strategy for CO2 utilization, but its intricate transformation pathways and insufficient product selectivity still pose challenges. Exploiting new catalysts for tuning product selectivity in CO2 hydrogenation is important to improve the viability of this technology, where reverse water-gas shift (RWGS) and methanation as competitive reactions play key roles in controlling product selectivity in CO2 hydrogenation. So far, a series of metal-based catalysts with adjustable strong metal–support interactions, metal surface structure, and local environment of active sites have been developed, significantly tuning the product selectivity in CO2 hydrogenation. Herein, we describe the recent advances in the fundamental understanding of the two reactions in CO2 hydrogenation, in terms of emerging new catalysts which regulate the catalytic structure and switch reaction pathways, where the strong metal–support interactions, metal surface structure, and local environment of the active sites are particularly discussed. They are expected to enable efficient catalyst design for minimizing the deep hydrogenation and controlling the reaction towards the RWGS reaction. Finally, the potential utilization of these strategies for improving the performance of industrial catalysts is examined.

A series of metal oxide, phosphate, alloy, and carbide-based catalysts for selective CO2 hydrogenation are summarized, showing their abilities to switch CO2 methanation to RWGS.  相似文献   

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Studies of catalytic CO hydrogenation following the Langmuir-Hinshelwood mechanism indicate that the observed decrease in the activation energy with increasing temperature is due to the decreased surface coverage with reactants. The relationships obtained permit to carry out approximate estimates for the adsorption heat of CO.
CO, -, , . CO.
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Conclusions When the hydrogenation of dehydrolinalool to linalool is run on a Pd alloy containing 6 wt.% of Ru, which is lean in the -hydrogen phase, the selectivity is much greater than when the amount of the -hydrogen phase is greater. A high selectivity of the hydrogenation is achieved by reducing to a definite limit the amount of hydrogen in the membrane catalyst without using inhibitors of the side reactions, which can contaminate the hydrogenation products.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 926–928, April, 1984.  相似文献   

11.
The addition of carbon dioxide and water enhances acetophenone hydrogenation activity over an activated carbon-supported palladium catalyst, and 1-phenylethanol can be easily recovered without distillation and neutralization. Two liquid phases (water and acetophenone) are indispensable for enhancement of the hydrogenation rate.  相似文献   

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Light-driven conversion of CO2into chemicals/fuels is a desirable approach for achieving carbon neutrality using clean and sustainable energy.However,its scale-up application is restricted due to insufficient efficiency.Herein,we present a photothermal catalytic hydrogenation of CO2into CH4over Ru/black Ti O2catalysts,aiming to achieve the synergistic use of light and heat in solar energy during CO2conversion.Owing to the desirable spectral ...  相似文献   

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The liquid phase hydrogenation of naphthalene was performed in the presence of CO over a commercial Ni/SiO2-Al2O3 catalyst. Naphthalene was hydrogenated even in the presence of CO at elevated temperatures, accompanying the hydrogenation of CO. Two activation energy values were obtained for the naphthalene hydrogenation depending on the reaction temperature. FT-IR measurement of the adsorbed CO was also carried out. Hydrogenation of the adsorbed CO created sites active for naphthalene hydrogenation.  相似文献   

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Kinetics of CO hydrogenation on supported Group VIII metals has been studied. Kinetic equations for CO methanation and Fischer-Tropsch synthesis suggested previously are consistent with the experimental data obtained.
CO VIII . CO -, , .
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A Ni-La/SiO2 catalyst was prepared through the incipient wetness impregnation method and tested in the oxidative dehydrogenation of ethane (ODHE) with CO2. The fresh and used catalysts were characterized by XRD and SEM techniques. The Ni-La/SiO2 catalyst exhibited catalytic activity for the oxidative dehydrogenation of ethane, but with low ethylene selectivity in the absence of methane. The selectivity to ethylene increased with increasing molar ratio of methane in the feed. The carbon deposited on the catalyst surface in the sole ODHE with CO2 was mainly inert carbon, while much more filamentous carbon was formed in the presence of methane. The filamentous carbon was easy to be removed by CO2, which might play a role in improving the conversion of ethane to ethylene. The introduction of methane might affect the equilibrium of the CO2 reforming of ethane and the ODHE with CO2. As a consequence, the synthesis gas produced from CO2 reforming of methane partly inhibited the reaction of ethane and promoted the ODHE with CO2, thus increasing the selectivity of ethylene.  相似文献   

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An antibatic relation has been established between the catalytic activities r of metals in relation to hydrogenation of CO and the selectivity in relation to methane . A mechanism is proposed for the reaction which makes it possible to interpret the observed kinetic relationships, the sequences of activities and selectivities, and also the relation between r and .Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 21, No. 5, pp. 549–553, September–October, 1985.  相似文献   

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The kinetics of methylcyclopentane hydrogenolysis on a Pt/Al2O3 catalyst (10% Pt) has been studied at 230°C. The selectivity to 2-methyl- and methylpentane formation depends on the partial pressures of the starting reactants (methylcyclopentane and hydrogen); the surface coverage by these reactants must be taken into account in selectivity studies.
Pt/Al2O3 (10% Pt) 230°C. 2-- 3- ( ). .
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采用定向同晶取代法制备了一系列镍孔雀石前驱体的Cu-Ni双金属催化剂。考察了前驱体结构以及催化剂表面组成对催化剂催化性能的影响,并采用浆态床反应器对催化剂的CO加氢制乙醇性能进行评价。实验结果表明,采用定向同晶取代法可以制备出(Cu,Ni)2CO3(OH)2纯物相,取代后的Ni2+主要富集在前驱体(Cu,Ni)2CO3(OH)2表面。焙烧后形成的(Cux,Ni1-x)O固溶体均匀地分散在CuO晶体结构中。还原后的催化剂中Cu、Ni相互均匀分散形成活性界面,促进了低碳醇的合成。其中,不连续分布的Ni活性位点阻止了碳链的进一步增长,从而提高了乙醇选择性。当Ni/Cu原料比为45:100时,(Cux,Ni1-x)O固溶体与CuO之间有较强的相互作用,表现出最好的反应活性和乙醇选择性。  相似文献   

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Acrylonitrile can be selectively hydrogenated into propionitrile at about 400 K over a ceramic-supported Ni catalyst. At low surface coverages, the observed rates of hydrogenation are proportional to the first powers of the partial pressures of both acrylonitrile and dihydrogen, in agreement with Langmuir-Hinshelwood kinetics.
400 . , , -.
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