| 摘要 |
An upstream catalyst (3) and a downstream catalyst (4) are disposed in an exhaust passage (2) of an engine (1). The downstream catalyst (4) contains in the same catalyst layer thereof Rh-doped CeZrNd mixed oxide particles on which Rh is supported and active alumina particles on which Pt is supported. The upstream catalyst (3) is a three-way catalyst containing an oxygen storage component having a lower oxygen storage capacity than the Rh-doped CeZrNd mixed oxide. |
