物理化学学报 >> 2009, Vol. 25 >> Issue (01): 79-85.doi: 10.3866/PKU.WHXB20090114

研究论文 上一篇    下一篇

类水滑石衍生CuAlO催化剂同时去除碳颗粒和氮氧化物

王仲鹏; 陈铭夏; 上官文峰   

  1. 上海交通大学机械与动力工程学院,燃烧与环境技术研究中心, 上海 200240; 济南大学化学化工学院, 济南 250022
  • 收稿日期:2008-07-14 修回日期:2008-10-07 发布日期:2008-12-31
  • 通讯作者: 上官文峰 E-mail:shangguan@sjtu.edu.cn

Simultaneous Catalytic Removal of NOx and Diesel Soot over Cu-Containing Hydrotalcite Derived Catalysts

WANG Zhong-Peng; CHEN Ming-Xia; SHANGGUAN Wen-Feng   

  1. Research Center for Combustion and Environmental Technology, School of Mechanical and Power Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China; School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China
  • Received:2008-07-14 Revised:2008-10-07 Published:2008-12-31
  • Contact: SHANGGUAN Wen-Feng E-mail:shangguan@sjtu.edu.cn

摘要: 以共沉淀法合成的含Cu类水滑石为前驱物, 制备了具有介孔结构的CuAlO复合氧化物催化剂, 采用程序升温反应技术评价了催化剂同时去除碳颗粒物(soot)和氮氧化物的性能, 并系统分析了反应条件对催化活性的影响. 结果表明, 在紧接触和松接触两种条件下, CuAlO都有较高的同时去除碳颗粒物和NOx的催化活性, 当催化剂与soot由紧接触变为松接触时, 起燃温度(Ti)由260 ℃升高到314 ℃, NO转化为N2的最大转化率(XN2-max)值由40.4%下降为29.2%; soot含量不同对Ti影响不大, Ti都在260 ℃左右; NO浓度或O2浓度增加, Ti下降, O2浓度从2.5%增至7.5%时对XN2-max影响不大, 都在40%左右; 反应气流速增大, soot起燃温度Ti基本不变, 都在260 ℃左右, 而XN2-max随气速增加而减小, 当气速从20 mL·min-1升至80 mL·min-1时, XN2-max由40.4%下降至21.6%, 但生成N2的量基本相同, 这取决于催化剂的选择性. 催化剂经重复使用后活性下降, 可能是由于反应过程中生成的中间产物吸附于催化剂表面, 覆盖了催化剂表面的活性位.

关键词: 水滑石, 复合氧化物, 碳颗粒物, 氮氧化物, 催化去除

Abstract: Copper-containing mixed oxides (CuAlO) were derived from hydrotalcites and prepared by co-precipitation and thermal evolution methods. The catalytic activity of the CuAlO was investigated for the simultaneous catalytic removal of NOx and diesel soot particulates by a temperature-programmed reaction (TPR) technique in a fixed-bed flow reactor. CuAlO showed good activity for the NOx-soot removal reaction under both tight and loose contact conditions. When the contact conditions between catalyst and soot changed from tight to loose, the ignition temperature (Ti) increased from 260 ℃ to 314 ℃ while the maximum conversion of NO to N2 (XN2-max) decreased from 40.4%to 29.2%. Soot content had no effect on the ignition temperature and all the Ti values were about 260 ℃ for different soot content. With an increase in NO concentration or O2 concentration the Ti value decreased. XN2-max values were about 40% when the O2 concentration changed from 2.5% to 7.5%. The total flow rate had no effect on the Ti values, while the XN2-max decreased from40.4%to 21.6%when the total flowrate increased from20 to 80 mL·min-1. Catalytic activity decreased when the catalyst was reused and this decrease may be related to an intermediate absorbed on the catalyst surface.

Key words: Hydrotalcite, Mixed oxide, Soot, NOx, Catalytic removal

MSC2000: 

  • O643