Acta Chimica Sinica ›› 2009, Vol. 67 ›› Issue (22): 2573-2578. Previous Articles     Next Articles

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沉淀剂种类对Ru/CeO2氨合成催化剂结构和性能的影响

罗小军   王榕    倪军    林建新    魏可镁   

  1. (福州大学化肥催化剂国家工程研究中心 福州 350002)
  • 投稿日期:2009-05-23 修回日期:2009-06-25 发布日期:2009-07-14
  • 通讯作者: 王榕 E-mail:rwang@fzu.edu.cn

Effect of Precipitants on Structure and Catalytic Activity of Ru/CeO2 Catalysts for Ammonia Synthesis

Luo, Xiaojun,Wang, Rong*,Ni, Jun,Lin, Jianxin,Wei, Kemei   

  1. (National Research Center of Chemical Fertilizer Catalysts, Fuzhou University, Fuzhou 350002)
  • Received:2009-05-23 Revised:2009-06-25 Published:2009-07-14

Ru/CeO2 catalysts were prepared by the co-precipitation method using six precipitants, K2CO3, NH3•H2O, (NH4)2CO3, KOH, NH4HCO3 and KHCO3, used for the ammonia synthesis and characterized by N2 adsorption-desorption, X-ray fluorescence spectroscopy, X-ray diffraction and H2 temperature-pro- grammed reduction to explore the cause resulting in their significant difference of catalytic activity. The ammonia synthesis activity of Ru/CeO2 catalyst prepared using NH4HCO3 as the precipitant was 14.46% at 10 MPa, 10000 h-1, 450 ℃, which was higher than those obtained by other precipitants. The samples prepared using the rest four precipitants presented lower activity for ammonia synthesis. The type of precipitant not only significantly affects the coprecipitation of ruthenium and cerium ions, but also affects the reduction of the surface oxygen. The high catalytic activity of Ru/CeO2 catalyst prepared using NH4HCO3 can be attributed to the synergism among the increase in ruthenium loading, the higher dispersion of ruthenium particles, and the easier reduction of surface oxygen of the support.

Key words: ammonia synthesis, precipitant, cerium, ruthenium, co-precipitation