化学学报 ›› 2012, Vol. 70 ›› Issue (02): 137-142.DOI: 10.6023/A1107121 上一篇    下一篇

研究论文

沉淀方式对氧化还原共沉淀制备Ru/CeO2 氨合成催化剂结构与性能的影响

林建新, 张留明, 倪军, 王榕, 魏可镁   

  1. 福州大学化肥催化剂国家工程研究中心 福州 350002
  • 收稿日期:2011-06-28 修回日期:2011-09-26 出版日期:2012-01-28 发布日期:2012-02-25
  • 通讯作者: 林建新 E-mail:lin3jx@fzu.edu.cn
  • 基金资助:

    中国石油科技创新基金研究(No.2010D-5006-0502)和国家科技支撑计划(No.2007BAE08B02)资助项目.

Effect of Redox Co-precipitation Methods on Structure and Catalytic Activity of Ru/CeO2 Catalysts for Ammonia Synthesis

Lin Jianxin, Zhang Liuming, Ni Jun, Wang Rong, Wei Kemei   

  1. National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou 350002
  • Received:2011-06-28 Revised:2011-09-26 Online:2012-01-28 Published:2012-02-25
  • Supported by:

    Project supported by Innovation Fund of China National Petroleum Corporation (No.2010D-5006-0502) and National Science and Technology Support Program of China (No.2007BAE08B02).

采用氧化还原共沉淀法制备了Ru/CeO2 氨合成催化剂, 并运用N2 物理吸附、X 射线衍射(XRD)、场发射扫描电镜(FE-SEM)、CO 吸附和H2 程序升温还原(H2-TPR)等技术对其进行了表征, 考察了沉淀时反应液的并流、反加、正加对所制备的 Ru/CeO2 催化剂氨合成性能的影响. 结果表明, 不同沉淀方式所得到的催化剂, 催化剂的表面织构和金属钌的分散度都存在明显的差别, 最终影响了催化剂的氨合成活性, 其中采用反加法制备的催化剂上钌的分散度(45.6%)和还原性最好, 比表面积最大(120 m2/g), 因而催化活性最高, 在10 MPa, 10000 h-1, 425 ℃反应时, 出口NH3 浓度达到12.6%.

关键词: 氧化还原共沉淀法, 氨合成, 二氧化铈,

The Ru/CeO2 catalyst was prepared by redox co-precipitation methods, including normal precipitation, reverse precipitation and parallel flow precipitation. The obtained catalysts were characterized by N2 physisorption, X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), CO chemisorption, and field-emission scanning electron microscopy (FE-SEM). The obvious difference of Ru dispersion and surface texture exist in the catalysts prepared by different methods. The activity test showed that the ammonia synthesis activity of the Ru/CeO2 catalyst prepared by reverse precipitation was 12.6% at 10 MPa, 10000 h-1, and 425 ℃, which was much higher than those obtained by other methods. Such a high catalytic attributes to three facts: the easier reduction, the much higher dispersion of Ru (45.6%) and bigger surface area (120 m2/g).

Key words: redox co-precipitation, ammonia synthesis, cerium dioxide, ruthenium