| abstract |
The invention is a method and system for treatingnexhaust gases generated by a diesel engine by locating twoncatalyst components in the engine exhaust gas passage. Thenfirst catalyst component which exposed to oxidizing dieselnexhaust is located nearest to the engine and is a nitrogennoxide absorbent made of support material carrying preciousnmetal. The second component is a catalyst such as a lean-NOxncatalyst or a selective reduction catalyst which is capablenof converting the exhaust gas passing over it includingnreducing the nitrogen oxides desorbed from the firstncomponent into nitrogen (N 2 ) or nitrous oxide (N 2 O).nMaterials like hydrocarbons or ammonia or urea may beninjected into the vicinity of the second catalyst componentnto aid in the reduction. |