Catalysts to reduce NOx in an exhaust gas stream and methods of preparation

摘要

Catalysts, systems and methods are described to reduce NOx emissions of an internal combustion engine. In one embodiment, an emissions treatment system for an exhaust stream is provided having a catalyst comprising silver and a platinum group metal on a particulate alumina support, the atomic fraction of the platinum group metal being less than or equal to about 0.25. Methods of manufacturing catalysts are described in which silver is impregnated on alumina particles.