| 摘要 |
PROBLEM TO BE SOLVED: To provide a catalyst apparatus which effectively purifies an exhaust gas containing a plenty of pentanes and CO discharged following upon HCCI combustion from a gasoline engine.SOLUTION: Each of a first catalyst 27 in the upper flowing side and a second catalyst 28 on the lower flowing side includes Pt and Rh as catalyst metals, and in each of the catalyst 27, 28, Pt is supported on only active alumina and Rh is supported on or doped in at least one of a Ce containing oxide and a Ce non-containing oxide, wherein the Pt/Rh mass ratio of the first catalyst 27 is ≥4 times and ≤10 times the Pt/Rh mass ratio of the second catalyst 28. |
