Hydrogenation of CO on molybdenum and cobalt molybdenum carbide catalysts¡ªMass and infrared spectroscopy studies

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• 作者：Yusuke Aoki ; Hiroyuki Tominaga ; Masatoshi Nagai
• 关键词：Cobalt molybdenum carbide ; CO hydrogenation ; Methane ; Mass and infrared spectroscopies
• 刊名：Catalysis Today
• 出版年：2013
• 出版时间：15 October, 2013
• 年：2013
• 卷：215
• 期：Complete
• 页码：169-175
• 全文大小：1360 K

文摘

The hydrogenation of CO on Mo and CoMo carbide catalysts was evaluated by quadrupole mass (MS) and in situ infrared (FTIR) spectroscopic measurements. The difference in the catalytic properties of the Mo and CoMo carbides and the role of the Co atom in the catalytic activity were determined. The surface-adsorbed-species-derived CO and H₂ were estimated using C¹⁸O for the 973 K-carburized CoMo catalyst by MS spectrometry in flowing 2 % CO/61 % H₂ with a He balance at 453 K, showing that the C¹⁸O was dissociated to form H₂¹⁸O and C¹⁸O¹⁶O. The H₂ introduction formed a significant amount of CH₄ together with a small amount of H₂¹⁶O without H₂¹⁸O. As a result, CO was dissociatively adsorbed on the CoMo carbide by the H₂ introduction to form the OH group and CH₄. A slight amount of CO₂ was formed during the reaction on the CoMo carbide catalyst, which was different from the formation of CO₂ on the 973 K-carburized Mo catalyst. The introduction of Co to Mo₂C prevented the water-gas shift reaction. The CH₄ gas band at 3016 cm^?1 was detected and significantly increased after the appearance of the bands for the surface OH species at 3570-3760 cm^?1 on the surface of the 873 K-carburized Mo catalyst. The formation of H₂O preceded the formation of CH₄.