用脉冲D_2反应研究CeO_2在Co-CeO_2/SiO_2费托合成催化剂中的促进作用机理  

Studies on Promotion Mechanism of CeO_2 in Co-CeO_2/SiO_2 Catalyst for Fischer-Tropsch Synthesis Using D_2 Pulse Reaction

作　　者：师海波[1] 沈师孔[1] 

机构地区：[1]中国石油大学(北京)中国石油天然气总公司催化重点实验室,北京102249

出　　处：《催化学报》2006年第12期1096-1100,共5页

基　　金：国家重点基础研究发展计划(973计划)资助项目(2005CB221402).

摘　　要：采用脉冲D2反应研究了CeO2在Co-CeO2/SiO2费托合成催化剂中的作用机理.通过比较在Co-CeO2/SiO2和Co/SiO2催化剂上的脉冲D2反应实验结果发现,CeO2可以提高载体表面Si-OH的H-D同位素交换活性和Si-OH中H参与CO加氢反应的活性;CeO2不仅增加了催化剂表面活性碳物种的总量,而且活性碳物种以链增长单体-CH2-为主,因而有利于增加费托合成反应速率和链增长几率;CeO2的加入明显提高了催化剂表面碳原子的加氢反应速率,从而减少了碳沉积.The role of the CeO2 promoter in the Co-CeO2/SiO2 catalyst playing in Fischer-Tropsch synthesis （FTS） was investigated by means of the D2 pulse reaction. The D2 pulse reaction results over Co-CeO2/SiO2 and Co/SiO2 catalysts showed that the addition of CeO2 increased the catalytic activity of Co/SiO2 for the H-D isotopic exchange and the reactivity of H from Si-OH for CO hydrogenation. The addition of CeO2 increased the total amount of active carbon species on the surface of Co/SiO2 and made the chain growth unit -CH2- the dominating one, which consequently benefited the increase of the FTS reactivity and the chain growth possibili- ty. The addition of CeO2 into Co/SiO2 also improved the hydrogenation reactivity of carbon atoms on the surface of Co-CeO2/SiO2, which led to a decrease in carbon deposition.

关 键 词：钻 氧化铈 二氧化硅 负载型催化剂 助剂 费托合成 脉冲D2反应 H—D同位素交换 

分 类 号：O643.32[理学—物理化学]