中文摘要：

将Ag-Rh浸渍到共沉淀法合成的Ce-Zr-Al上,制备出Ag（0.04）-Rh（x）/Ce0.5Zr0.5O2-75%Al2O3系列催化剂,采用BET比表面积、X射线衍射光谱（XRD）和原位漫反射傅里叶变换红外光谱（DRIFTS）对催化剂进行表征,并探讨催化剂在贫燃条件下选择性还原NO的活性和反应机理.结果表明,Ag-Rh双组分催化剂的活性较单组分Ag、Rh催化剂的高.Rh负载量为0.7%（质量分数）时,NO转化率达最佳（90.3%）,且反应的起燃温度低、活性温度范围宽（300～500℃）.DRIFTS结果显示,Rh的添加不仅有利于催化剂表面NO的吸附,而且能促进Ag催化生成关键反应中间体—CO—NH—,进而显著提高NO的转化率.

英文摘要：

Ag-Rh was impregnated on coprecipitated Ce-Zr-Al to prepare a series of Ag（0.04）-Rh（x）/Ce0.5Zr0.5O2-75%Al2O3 catalysts,and the catalysts were characterized using BET,XRD and in situ DRIFTS technologies. The activities of the catalysts for selective reduction of NO under lean-burn conditions,and the reaction mechanism were investigated. The results showed that the Ag-Rh catalysts exhibited higher catalytic performances than the single-component Ag or Rh catalysts. The highest NO conversion of 90.3% was achieved with a Rh loading of 0.7 wt%,accompanied by a lower light-off temperature and wider activity window （300～500℃）.The in situ DRIFTS results indicated that the addition of Rh not only favored the adsorption of NO on the catalyst surface,but also promoted the formation of the crucial intermediate of —CO—NH— by Ag,thus enhancing the NO conversion notably.