催化学报 ›› 2012, Vol. 33 ›› Issue (12): 1927-1937.DOI: 10.1016/S1872-2067(11)60467-1

• 研究论文 • 上一篇    下一篇

不同 Mn/(Mn+Ce) 质量比对整体式 MnOx-CeO2/WO3-ZrO2 催化剂 NH3-SCR 性能的影响

徐海迪, 房志涛, 曹毅, 孔爽, 林涛a, 龚茂初, 陈耀强b   

  1. 四川大学化学学院, 教育部绿色化学与技术重点实验室, 四川成都 610064
  • 收稿日期:2012-08-14 修回日期:2012-10-08 出版日期:2013-01-18 发布日期:2012-12-18

Influence of Mn/(Mn+Ce) Ratio of MnOx-CeO2/WO3-ZrO2 Monolith Catalyst on Selective Catalytic Reduction of NOx with Ammonia

XU Haidi, FANG Zhitao, CAO Yi, KONG Shuang, LIN Taoa, GONG Maochu, CHEN Yaoqiangb   

  1. Key Laboratory of Green Chemistry & Technology of the Ministry of Education, College of chemistry, Sichuan University, Chengdu 610064, Sichuan, China
  • Received:2012-08-14 Revised:2012-10-08 Online:2013-01-18 Published:2012-12-18

摘要: 制备了一系列不同 Mn/(Mn+Ce) 质量比的 MnOx-CeO2/WO3-ZrO2 整体式催化剂用于富氧条件下的 NH3 选择性催化还原 NOx (NH3-SCR), 并采用 N2 吸脱附、储氧量、X 射线衍射、X 光电子能谱、NH3/NO 程序升温脱附以及 H2 程序升温还原等手段对催化剂进行表征. 结果表明, 当 Mn/(Mn+Ce) 质量比为 0.5 时, 整体式催化剂具有较好的 NH3-SCR 性能, 在空速 10000 h-1和 173~355 ºC 条件反应下, NOx 转化率达 90% 以上. 这是由于该 MnOx-CeO2/WO3-ZrO2 催化剂具有更高的 NO 氧化活性、更高的表面 Ce 和 Mn 原子浓度以及 Ce3+/Ce 值较低的 NH3 和 NO 脱附温度以及优异的氧化还原性能所致.

关键词: 锰, 铈, 氨选择性催化还原, 氮氧化物, 质量比

Abstract: A series of monolith MnOx-CeO2/WO3-ZrO2 catalysts with different mass ratios of Mn/(Mn+Ce) were prepared and used for the selective catalytic reduction (SCR) of NOx with NH3 in the presence of excess O2. The catalysts were characterized by N2 adsorption, oxygen storage capacity, X-ray diffraction, X-ray photoelectron spectroscopy, NH3/NO temperature-programmed desorption, and H2 temperature-programmed reduction. The best catalyst had the mass ratio of Mn/(Mn+Ce) = 0.5. It gave 90% NOx conversion in the range of 173-355 ºC at the gas hourly space velocity of 10000 h-1, and characterization results showed that a higher oxidation activity of NO to NO2, more surface Ce and Mn with a larger Ce3+/Ce4+ ratio, lower NH3 and NO desorption temperatures, and excellent redox ability were together responsible for its best NH3-SCR performance.

Key words: manganese, cerium, selective catalytic reduction of ammonia, nitrogen oxide, mass ratio