催化学报 ›› 2012, Vol. 33 ›› Issue (3): 536-542.DOI: 10.3724/SP.J.1088.2012.10949

• 研究论文 • 上一篇    下一篇

Pr 掺杂对 Ru/CeO2 催化剂结构和氨合成性能的影响

林建新*, 张留明, 王自庆, 王榕, 魏可镁   

  1. 福州大学化肥催化剂国家工程研究中心, 福建福州 350002
  • 收稿日期:2011-09-26 修回日期:2011-11-04 出版日期:2012-03-15 发布日期:2015-07-27

Effects of Pr Doping on Structure and Catalytic Performance of Ru/CeO2 Catalyst for Ammonia Synthesis

LIN Jianxin*, ZHANG Liuming, WANG Ziqing, WANG Rong, WEI Kemei   

  1. National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou 350002, Fujian, China
  • Received:2011-09-26 Revised:2011-11-04 Online:2012-03-15 Published:2015-07-27

摘要: 采用氧化-还原共沉淀法制备了 Pr 掺杂的 Ru/CeO2-PrO2 氨合成催化剂, 并运用 N2 物理吸附、X 射线粉末衍射、H2 程序升温还原、CO 化学吸附、N2 程序升温脱附、场发射扫描电镜、高分辨透射电镜和 X 射线光电子能谱等技术对其进行了表征, 考察了 Pr 添加量对催化剂表面结构和性能的影响. 结果表明, Pr 掺杂对 Ru/CeO2 催化剂的比表面积和 Ru 分散度都有所影响. 当 CeO2 中 Pr 掺杂量为 4% 时, 在 425 ºC, 10 MPa, 10000 h–1 的反应条件下, 氨合成转化频率可达到 12.13 × 10–2 s–1, 较 Ru/CeO2 催化剂提高了 58%, 这主要归结于复合材料电子传导性能的提高.

关键词: 镨, 二氧化铈, 钌, 负载型催化剂, 氨合成, 电子传递

Abstract: The Pr-doped ceria supported ruthenium catalyst Ru/CeO2-PrO2 for ammonia synthesis was prepared by a redox co-precipitation method. The obtained catalyst samples were characterized by N2 physisorption, X-ray diffraction, H2 temperature-programmed reduction, CO chemisorption, temperature-programmed desorption of nitrogen, field-emission scanning electron microscopy, high resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The effects of Pr doping amount on the microstructure and catalytic properties of Ru/CeO2-PrO2 were investigated. The results showed that the composite oxide created form Pr-doped ceria has some influence on the Ru dispersion and surface texture. The activity test showed that the ammonia synthesis transformation frequency over the Ru/CeO2-PrO2 catalyst with 4% Pr was 12.13 × 10–2 s–1 at 10 MPa, 10000 h–1, and 425 ºC, which was 58% higher than that of Ru/CeO2. The improvement of electrical conductivity performance is the key factor for the higher catalytic activity.

Key words: praseodymium, ceria, ruthenium, supported catalyst, ammonia synthesis