催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (12): 1096-1100.

• 研究论文 • 上一篇    下一篇

用脉冲D2反应研究CeO2在Co-CeO2/SiO2费托合成催化剂中的促进作用机理

师海波,沈师孔   

  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
  • 收稿日期:2006-12-25 出版日期:2006-12-25 发布日期:2006-12-25

Studies on Promotion Mechanism of CeO2 in Co-CeO2/SiO2 Catalyst for Fischer-Tropsch Synthesis Using D2 Pulse Reaction

SHI Haibo, SHEN Shikong*   

  1. The Key Laboratory of Catalysis of CNPC, China University of Petroleum, Beijing 102249, China
  • Received:2006-12-25 Online:2006-12-25 Published:2006-12-25

PDF

852

被引次数

17

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.

关键词: 钴, 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

Abstract: 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 -[KG-20x]CH2[KG-45x]- the dominating one, which consequently benefited the increase of the FTS reactivity and the chain growth possibility. 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.

Key words: cobalt, ceria, silica, supported catalyst, promoter, Fischer-Tropsch synthesis, D2 pulse reaction, H-D isotopic exchange