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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (9): 1021-1027. 上一篇    下一篇

研究论文

应用原位漫反射红外-质谱技术研究CuO/Al2O3催化剂表面酸性及其反应性能

赵海红1，谢国勇*,2，刘振宇2，刘有智1   

  1. 中北大学化工与环境学院 太原 030051)
    (2中国科学院山西煤炭化学研究所煤转化国家重点实验室 太原 030001
  • 投稿日期:2007-09-18 修回日期:2007-12-03 发布日期:2008-05-14
  • 通讯作者: 谢国勇

A Combined in-situ Diffuse Reflectance FTIR and On-line Mass Spectroscopy Study of Surface Acidity and Reactivity over a CuO/Al2O3 Catalyst

ZHAO Hai-Hong1 XIE Guo-Yong*2 LIU Zhen-Yu2 LIU You-Zhi1   

  1. (1 College of Chemical and Environmental Engineering, North University of China, Taiyuan 030051)
    (2 State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001)
  • Received:2007-09-18 Revised:2007-12-03 Published:2008-05-14
  • Contact: XIE Guo-Yong

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应用原位漫反射红外-质谱联用、程序升温和暂态响应技术研究了CuO/Al2O3催化剂表面酸性及其反应性能. 实验结果表明, CuO/Al2O3催化剂表面呈Lewis酸性, 硫化不仅可增强CuO/Al2O3催化剂的Lewis酸性, 而且可产生新的Brønsted酸性位; 吸附于Lewis酸性位的NH3具有选择性催化还原(SCR)活性. 而在硫化样Cu8(400S)中Lewis和Brønsted酸性位同时存在的情况下, 吸附于Lewis和Brønsted酸性位的氨均具有SCR活性, 且后者较前者弱; CuO/Al2O3催化剂上的SCR反应遵循Eley-Rideal机理, 即SCR反应发生于吸附态NH3与气相NO之间.

关键词: 原位漫反射红外, 在线质谱, CuO/Al2O3, 选择性催化还原(SCR), 表面酸性

Combined in situ diffuse reflectance FTIR (DRIFT) and on-line mass spectroscopy, temperature-programmed and transient experiments were performed to evaluate the surface acidity and reactivity of a CuO/Al2O3 catalyst. The results show that only ammonia coordinated at Lewis acid sites was found on the CuO/Al2O3 catalyst. Sulfation of CuO/Al2O3 catalyst greatly increases the concentration and strength of the Lewis acid sites and the concentration of Brønsted acid sites. Ammonia adsorbed both on Lewis acid sites and Brønsted acid sites plays an important role in the selective catalytic reduction of NO over the CuO/Al2O3 catalyst-sorbents, which occurs between the adsorbed ammonia and gaseous NO, following an Eley-Rideal mechanism.

Key words: in situ diffuse reflectance FTIR (DRIFT), on-line mass spectroscopy, CuO/Al2O3, selective catalytic reduction (SCR), surface acidity