| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the content of a pollutant contained in an engine exhaust flow. <P>SOLUTION: An engine exhaust treatment apparatus and a method of using it includes an upstream catalyst and a downstream catalyst. The upstream catalyst includes a catalyst metal demonstrating effect at least in oxidation of hydrocarbon contained in the exhaust gas flow, preferably includes a palladium catalyst component, and does not substantially includes an oxygen storage component, i.e., oxides of cerium, cobalt, iron, molybdenum, nickel, praseodymium, tungsten and vanadium, but the downstream catalyst includes the oxygen storage component. Preferably, the upstream catalyst is a close coupled catalyst. The downstream catalyst may an underfloor catalyst or a close coupled catalyst, and preferably in this case, an additional underfloor catalyst is additionally used. <P>COPYRIGHT: (C)2009,JPO&INPIT |
