| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust gas cleaning catalyst which has high heat resistance and excellent oxygen storage performance, HC reforming performance and NOx cleaning performance, has high oxygen discharge property and durability further, and has a high pressure loss reducing effect as a catalyst.SOLUTION: An exhaust gas cleaning catalyst includes: a composite oxide support including alumina, zirconia, ceria, a first additive element oxide and a second additive element oxide comprising two kinds of elements selected from a group composed of rare earth elements excluding cerium or alkaline earth elements; and a precious metal catalyst supported on the composite oxide support. In the composite oxide support, alumina is contained in a range of 30 to 40 mass%, zirconia is contained in a range of 36 to 46 mass%. On at least a part of the respective surface layers of alumina, zirconia and ceria, a concentrated area where the content ratio of the second additive element oxide is high is formed. |
