Promotional effects of cerium modification of Cu-USY catalysts on the low temperature activity of NH3-SCR

摘要

A series of ceria-modified Cu-USY catalysts were prepared by a co-impregnation method and tested towards the selective reduction of NOx with NH3. A 5Cu-8Ce-USY catalyst with 8 wt% Ce content showed optimum low-temperature activity, and the widest NO conversion temperature window (160-410 degrees C) of operation, which these features are related to the enhanced redox ability and Cu+ species concentration in the sodalite cage compared to the Cu-USY catalyst. In addition, Lewis acid sites on the surface of Cu-Ce-USY catalysts were found to play a key role for its excellent SCR performance. The ceria-modified Cu-USY catalysts with enhanced low-temperature (120-170 degrees C) deNO(x) performance make them highly promising candidates for practical applications in controlling NOx emissions.