| 摘要 |
PROBLEM TO BE SOLVED: To provide a catalytic converter excellent in OSC performance and NOx purification performance.SOLUTION: The catalytic converter 10 includes a substrate 1 having a cell structure through which exhaust gas is circulated and a catalyst layer 3 formed on the cell wall 2 of the substrate 1. The substrate layer 3 has an under catalyst layer 4 at the surface of the substrate 1 along the whole length, and a first upper catalyst layer 6 upstream of the flow direction of exhaust gas and a second upper catalyst layer 7 downstream of the flow direction at the surface of the under catalyst layer 4. The under catalyst layer 4 includes a carrier and palladium. The first upper catalyst layer 6 includes rhodium and a zirconia composite oxide carrier containing ceria. The second upper catalyst layer 7 includes rhodium and a zirconia composite oxide carrier containing no ceria. The first upper catalyst layer 6 is formed in the range of X% (30 to 70%) of the whole length of the substrate, with an origin at the upstream end of the substrate 1. The second upper catalyst layer 7 is formed in the range of 100-X% of the whole length of the substrate 1, with an origin at the downstream end of the substrate 1. |
