| 摘要 |
PURPOSE:To provide the subject a catalyst capable of improving purifying performance by considering not only the anti-positioning property of palladium but heat resistance as a whole. CONSTITUTION:This catalyst consists of a catalyst carrier 2 and first, second and third catalyst layers 3, 4, 5, respectively successively formed in this order on the outer side of the carrier. The first and second catalyst layers 3, 4 are alumina layers and the third layer 5 consists of cerium oxide as the main component and alumina. Then palladium is incorporated in portions into either one of the first and second catalyst layers 3, 4 and into the third catalyst layer 5. The weight ratio of palladium in the third catalyst layer 5 to the palladium in the either one of the first and second catalyst layers 3, 4 is specified to 70:30 to 90:10. |
