(Ag/Al_2O_3+Cu/Ce(x)/Al_2O_3)组合催化剂催化乙醇选择性还原NO_x及其副产物的消除  

Selective Catalytic Reduction of NO_x by Ethanol and Removal of By-products over Combined Catalyst(Ag/Al_2O_3+Cu/Ce(x)/Al_2O_3)

作　　者：宋小萍[1] 张长斌[1] 贺泓[1] 

机构地区：[1]中国科学院生态环境研究中心,北京100085

出　　处：《催化学报》2008年第6期524-530,共7页

基　　金：国家高技术研究发展计划(863计划,2006AA060304,2006AA06A304);国家重点基础研究发展计划(973计划,2004CB719503)

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.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/A1203 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-ray diffraction, H2 temperature-programmed reduction, and X-ray photoelectron spectroscopy. The results showed that the interaction between Cu and Ce is the main factor causing the improvement of CO oxidation.

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 

分 类 号：O643.32[理学—物理化学]