催化学报 ›› 2008, Vol. 29 ›› Issue (6): 524-530.

• 研究论文 • 上一篇    下一篇

(Ag/Al2O3+Cu/Ce(x)/Al2O3)组合催化剂催化乙醇选择性还原NOx及其副产物的消除

宋小萍,张长斌,贺泓   

  1. 中国科学院生态环境研究中心, 北京 100085
  • 收稿日期:2008-06-25 出版日期:2008-06-25 发布日期:2012-04-28

Selective Catalytic Reduction of NOx by Ethanol and Removal of By-products over Combined Catalyst (Ag/Al2O3+Cu/Ce(x)/Al2O3)

SONG Xiaoping, ZHANG Changbin, HE Hong*   

  1. Research Center for Eco-Environmental Sciences, The Chinese Academy of Sciences, Beijing 100085, China
  • Received:2008-06-25 Online:2008-06-25 Published:2012-04-28

摘要: 制备了Cu/Ce(x)/Al2O3(x为Ce与Al的摩尔比)系列氧化催化剂,并考察了(Ag/Al2O3+Cu/Ce(x)/Al2O3)组合体系催化乙醇还原NOx以及氧化去除反应副产物(CO和未完全燃烧的碳氢化合物)的活性. 在200~350 ℃温度区间,组合催化剂具有与Ag/Al2O3相似的NOx去除效率. 随着Ce/Al比增加,氧化催化剂去除CO的活性逐渐提高. Cu/CeO2催化剂具有最好的氧化活性,但其对NOx的去除有较大影响. 综合考虑NOx转化率以及CO和HC的去除效果, (Ag/Al2O3+Cu/Ce(0.15)/Al2O3)是最佳的催化剂组合体系. 通过对此系列氧化催化剂的BET比表面积、XRD、H2-TPR以及XPS等表征结果的分析,发现Cu和Ce之间的相互作用是催化剂氧化CO能力提高的主要原因.

关键词: 银, 氧化铝, 氧化催化剂, 氧化铜, 氧化铈, 氮氧化物, 乙醇, 选择性催化还原, 一氧化碳, 未燃碳氢化合物

Abstract: The selective catalytic reduction of NOx by ethanol and the removal of by-products (CO and unburned hydrocarbons) were studied over (Ag/Al2O3+Cu/Ce(x)/Al2O3) (x: molar ratio of Ce to Al) combined catalysts. The combined catalysts showed similar NOx reduction activity to Ag/Al2O3 in the temperature range of 200-350 ℃. CO oxidation capabilities of the oxidation catalysts were improved with increasing Ce/Al ratio. Cu/CeO2 showed the best oxidation activity of CO but caused obvious decrease of NOx conversion when it was directly placed after Ag/Al2O3. (Ag/Al2O3+Cu/Ce(0.15)/Al2O3) was the best in the combined catalysts considering the conversions of NOx, CO, and hydrocarbons. The Cu/Ce(x)/Al2O3 oxidation catalysts were characterized by BET surface area measurement,X-raydiffraction, H2 temperature-programmed reduction, andX-rayphotoelectron spectroscopy. The results showed that the interaction between Cu and Ce is the main factor causing the improvement of CO oxidation.

Key words: silver, alumina, oxidation catalyst, copper oxide, cerium oxide, nitrogen oxide, ethanol, selective catalytic reduction, carbon monoxide, unburned hydrocarbons