催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (11): 976-982.

• 研究论文 • 上一篇    下一篇

乙醇水蒸气重整Co/CeO2催化剂

王红,刘鹏翔,刘源,秦永宁   

  1. 天津大学化工学院, 天津 300072
  • 收稿日期:2006-11-25 出版日期:2006-11-25 发布日期:2006-11-25

Co/CeO2 Catalysts for Steam Reforming of Ethanol

WANG Hong, LIU Pengxiang, LIU Yuan*, QIN Yongning   

  1. School of Chemical Engineering, Tianjin University, Tianjin 300072, China
  • Received:2006-11-25 Online:2006-11-25 Published:2006-11-25

PDF

884

被引次数

34

摘要： 采用共沉淀法制备了Co/CeO2催化剂并将其应用于乙醇水蒸气重整制氢反应,考察了活性组分含量和焙烧温度对催化剂性能的影响. 结果表明,在原料气水∶乙醇∶N2摩尔比为3∶1∶16, 空速为40 L/(g·h)和反应温度为350～600 ℃的条件下, 经650 ℃焙烧的10%Co/CeO2催化剂对乙醇水蒸气重整制氢反应具有高活性和高选择性. 在500 ℃下进行的40 h稳定性测试中,该催化剂上的乙醇转化率始终接近100%, 反应后气体中的H2含量保持在65%左右. X射线衍射表征结果显示,焙烧后催化剂的主要物相组成为Co3O4和CeO2, 二者之间存在相互作用. Co/CeO2催化剂中钴的主要存在形式包括小晶粒的钴氧化物、大晶粒Co3O4和进入CeO2晶格的钴,Co3O4含量和焙烧温度的改变可影响催化剂中钴的存在形式. 由催化剂中高分散小晶粒的钴氧化物还原所得的金属钴是关键的活性组分.

关键词: 乙醇, 水蒸气重整, 制氢, 钴, 氧化铈, 负载型催化剂

Abstract: The Co/CeO2 catalysts were prepared by the co-precipitation method and used for H2 production from steam reforming of ethanol. The effects of the Co3O4 content and calcination temperature on the catalyst performance were investigated. The Co/CeO2 catalyst with a Co3O4 content of 10% calcined at 650 ℃ exhibited high ethanol conversion and H2 selectivity under the reaction conditions of 350-600 ℃, water∶ethanol∶N2 molar ratio of 3∶1∶16, and space velocity of 40 L/(g•h). Over this catalyst, ethanol conversion and H2 selectivity kept close to 100% and 65%, respectively, during the stability test at 500 ℃ for 40 h. The catalysts were characterized by N2 adsorption using the BET method and X-ray diffraction. There are three kinds of cobalt in the catalyst, that is, highly dispersed cobalt oxide, bulk Co3O4, and cobalt ions in ceria lattice. It is supposed that the metallic cobalt from the reduction of highly dispersed cobalt oxide is the key active component of the Co/CeO2 catalyst.

Key words: ethanol, steam reforming, hydrogen production, cobalt, ceria, supported catalyst