催化学报

催化学报 ›› 2009, Vol. 30 ›› Issue (10): 973-975.

• 研究快讯 •    下一篇

Cr对In/WO3/ZrO2催化剂上甲烷选择性催化还原NO的促进作用

荆国华1,2, 李俊华1, 郝吉明1   

  1. 1 清华大学环境科学与工程系, 北京 100084 2 华侨大学环境科学与工程系, 福建厦门 361021
  • 收稿日期:2009-10-25 出版日期:2009-10-25 发布日期:2013-06-06

Promotional Effect of Cr on the Activity of In/WO3/ZrO2 for Selective Reduction of NO with Methane

JING Guohua1,2, LI Junhua1,*, HAO Jiming1   

  1. 1Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China 2Department of Environmental Science and Engineering, Huaqiao University, Xiamen 361021, China
  • Received:2009-10-25 Online:2009-10-25 Published:2013-06-06

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摘要： 分别采用浸渍法和机械混合法制备了 Cr 改性的 In/WO3/ZrO2 (In/WZr) 催化剂, 考察了改性前后催化剂的 CH4 选择性催化还原 NO 的活性. 结果表明, 将 Cr2O3 与 In/WZr 机械混合可显著提高 In/WZr 催化剂活性, Cr 的加入促进了气相中 NO 向 NO2 的转化. 而浸渍法制备的 Cr/In/WZr 催化剂活性远低于改性前的 In/WZr 催化剂, 这是由于在制备过程中部分 Cr2O3 转化为 CrO3, 使其氧化性大大提高, 从而将 CH4 完全氧化为 CO2 和 H2O, 不利于将 CH4 活化为反应所需的中间活性物种.

关键词: 氮氧化物, 选择性催化还原, 甲烷, 铟, 钨酸锆, 铬

Abstract: Cr-modified In/WO3/ZrO2 (In/WZr) catalysts were prepared by impregnation and mechanical mixing methods. Their activity for selective catalytic reduction of NO with CH4 was investigated. The results showed that the catalyst activity was enhanced by mixing Cr2O3 with In/WZr. The enhancement of the activity was due to the oxidation ability of Cr2O3, which improved the conversion of NO to NO2. However, for the catalysts prepared by impregnation, some of the trivalent chromium (Cr3+) was converted to Cr6+, which resulted in the lower activity than the initial In/WZr catalyst by the complete oxidation of CH4 to CO2 and H2O.

Key words: nitrogen oxide, selective catalytic reduction, methane, indium, tungstated zirconia, chromium