催化学报 ›› 2011, Vol. 32 ›› Issue (5): 727-735.DOI: 10.1016/S1872-2067(10)60220-3

• 研究论文 • 上一篇    下一篇

CeO2 添加对 Ag/Al2O3 催化剂低温氨氧化性能的影响

张丽, 刘福东a, 余运波, 刘永春, 张长斌, 贺泓b   

  1. 中国科学院生态环境研究中心, 环境化学与生态毒理学国家重点实验室, 北京 100085
  • 收稿日期:2011-01-04 修回日期:2011-02-23 出版日期:2011-05-31 发布日期:2014-09-29

Effects of Adding CeO2 to Ag/Al2O3 Catalyst for Ammonia Oxidation at Low Temperatures

ZHANG Li, LIU Fudonga, YU Yunbo, LIU Yongchun, ZHANG Changbin, HE Hongb   

  1. State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
  • Received:2011-01-04 Revised:2011-02-23 Online:2011-05-31 Published:2014-09-29

摘要: 采用活性测试和氮气吸附、X 射线衍射、X 射线光电子能谱、紫外-可见漫反射吸收光谱、高倍透射电镜、原位漫反射傅里叶变换红外光谱和 O2 脉冲吸附等研究了铈添加对 Ag/Al2O3 催化剂低温氨氧化性能的影响. 结果表明, 适量铈的添加可以明显促进 Ag/Al2O3 催化剂的低温氨氧化活性, 且对催化剂的选择性影响不大. 添加铈不仅可以促进 Ag/Al2O3 催化剂表面吸附和活化 O2 的能力, 而且可促进催化剂表面对氨的解离吸附和活化. 这是铈促进 Ag/Al2O3 催化剂低温氨氧化活性的主要原因.

关键词: 氨, 银, 铈, 氧化铝, 负载型催化剂, 氧气吸附, 高倍透射电镜, 原位漫反射傅里叶变换红外光谱

Abstract: The effects of adding CeO2 to Ag/Al2O3 on the selective catalytic oxidation of ammonia to nitrogen were investigated by activity test and N2 physisorption, X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis diffuse-reflectance spectroscopy, high resolution transmission electron microscopy, in situ diffuse reflectance infrared Fourier transform spectroscopy of NH3 adsorption, and O2-pulse adsorption. Adding a suitable amount of CeO2 improved the catalytic activity of Ag/Al2O3 for NH3 oxidation at temperatures below 160 oC, and slightly influenced N2 selectivity by improving the catalyst’s ability to adsorb and activate O2 and the adsorption and activation of NH3.

Key words: ammonia, silver, cerium, alumina oxide, supported catalyst, oxygen uptake, high resolution transmission electron microscopy, in situ diffuse reflectance infrared Fourier transform spectroscopy