物理化学学报 >> 2014, Vol. 30 >> Issue (6): 1175-1179.doi: 10.3866/PKU.WHXB201404171

催化和表面科学 上一篇    下一篇

焙烧温度对MnOx-CeO2-WO3-ZrO2催化剂上NH3选择性还原NO的影响

于在璐1, 谢鹏飞1, 唐幸福2, 乐英红1, 华伟明1, 高滋1   

  1. 1 复旦大学化学系, 上海市分子催化和功能材料重点实验室, 上海200433;
    2 复旦大学环境科学与工程系, 上海200433
  • 收稿日期:2014-03-10 修回日期:2014-04-17 发布日期:2014-05-26
  • 通讯作者: 乐英红，华伟明 E-mail:yhyue@fudan.edu.cn;wmhua@fudan.edu.cn
  • 基金资助:

    国家自然科学基金（21273043，21077026）及上海市科委（13DZ2275200）资助项目

Selective Catalytic Reduction of NO with NH3 over MnOx-CeO2-WO3-ZrO2：Effect of Calcination Temperature

YU Zai-Lu1, XIE Peng-Fei1, TANG Xing-Fu2, YUE Ying-Hong1, HUA Wei-Ming1, GAO Zi1   

  1. 1 Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Shanghai 200433, P. R. China;
    2 Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, P. R. China
  • Received:2014-03-10 Revised:2014-04-17 Published:2014-05-26
  • Contact: YUE Ying-Hong, HUA Wei-Ming E-mail:yhyue@fudan.edu.cn;wmhua@fudan.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21273043, 21077026) and Science and Technology Commission of Shanghai Municipality, China (13DZ2275200).

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摘要：

采用共沉淀法制备了MnOx-CeO2-WO3-ZrO2催化剂，考察了催化剂焙烧温度对O2和H2O存在下NH3选择性催化还原（NH3-SCR） NO的影响，并利用低温N2吸附、X射线衍射（XRD）、透射电镜（TEM）、X射线光电子能谱（XPS）、NH3程序升温脱附（NH3-TPD）和CO脉冲反应对催化剂进行了表征. 结果表明在NH3-SCR反应中，催化剂的低温活性随焙烧温度的提高而降低，这是由于催化剂表面化学吸附氧和酸性位减少引起的；催化剂的高温活性随焙烧温度的提高先增加后减小，这与催化剂表面最易释放氧数量的变化趋势相反. 700 ℃焙烧的催化剂具有良好的低温活性和最宽的反应温度窗口，在空速为90000 h-1的条件下，该催化剂的起燃温度（50% NO转化率）为189 ℃，且反应温度在218-431 ℃范围内，NO转化率可达到80%-100%.

关键词: 氮氧化物, 选择性催化还原, 氧化锰, 氧化铈, 氧化钨-氧化锆, 共沉淀法

Abstract:

MnOx-CeO2-WO3-ZrO2 catalysts were prepared by co-precipitation and calcined at various temperatures (500, 600, 700, and 800 ℃). The effect of calcination temperature on their performance in the selective catalytic reduction (SCR) of NO with ammonia in the presence of O2 and H2O was investigated. The structural and physicochemical characterization of the catalysts were performed by N2 adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), NH3 temperature-programmed desorption (NH3-TPD), and CO pulse reaction. The results show that the low temperature activity decreased with an increase in the calcination temperature, which is due to a decrease in the amount of surface chemisorbed oxygen and acid sites. As the calcination temperature increased the high temperature activity first increased and then decreased, which is contrary to the variation found for the most readily releasable oxygen on the catalyst surface. The catalyst calcined at 700 ℃ exhibited good low temperature activity and had the widest reaction temperature window. The light-off temperature (50% NO conversion) was 189 ℃ for this catalyst and the NO conversion was 80%-100% between 218 and 431 ℃ at a space velocity of 90000 h-1.

Key words: Nitrogen oxide, Selective catalytic reduction, Manganese oxide, Cerium oxide, WO3-ZrO2, Co-precipitation method