Catalytic properties of nanostructured Pd–Ag catalysts in the liquid-phase hydrogenation of terminal and internal alkynes

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• 作者：A. V. Rassolov ; P. V. Markov ; G. O. Bragina ; G. N. Baeva…
• 关键词：Pd–Ag ; liquid ; phase hydrogenation ; bimetallic catalysts ; nanoparticles ; terminal alkynes ; internal alkynes ; catalyst structure ; selectivity ; phenylacetylene ; diphenylacetylene
• 刊名：Kinetics and Catalysis
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：57
• 期：6
• 页码：853-858
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Catalysis; Physical Chemistry;
• 出版者：Pleiades Publishing
• ISSN：1608-3210
• 卷排序：57

文摘

A comparative catalytic study of Pd–Ag bimetallic catalysts and the commercial Lindlar catalyst (Pd–Pb/CaCO₃) has been carried out in the hydrogenation of phenylacetylene (PA) and diphenylacetylene (DPA). The Pd–Ag catalysts have been prepared using the heterobimetallic complex PdAg₂(OAc)₄(HOAc)₄ supported on MgAl₂O₄ and aluminas (α-Al₂O₃ and γ-Al₂O₃). Physicochemical studies have demonstrated that the reduction of supported Pd–Ag complex with hydrogen results in homogeneous Pd–Ag nanoparticles. Equal in selectivity to the Lindlar catalyst, the Pd–Ag catalysts are more active in DPA hydrogenation. The synthesized Pd–Ag catalysts are active and selective in PA hydrogenation as well, but the unfavorable ratio of the rates of the first and second stages of the process makes it difficult to kinetically control the reaction. The most promising results have been obtained for the Pd–Ag₂/α-Al₂O₃ catalyst. Although this catalyst is less active, it is very selective and allows efficient kinetic control of the process to be carried out owing to the fact that, with this catalyst, the rate of hydrogenation of the resulting styrene is much lower than the rate of hydrogenation of the initial PA.