| 摘要 |
PROBLEM TO BE SOLVED: To maintain high catalytic activity even after enduring exposure to high temperatures by forming a composite layer having Rh and Pt carried in coexistence by each of compound oxides A, B represented by a specific formula, on a heat-resistant support carrier and setting the weight of Rh carried by the compound oxide A not less than the weight of Rh carried by the compound oxide B. SOLUTION: A composite layer having Rh and Pt carried in coexistence by each of a compound oxide a represented by formula I (wherein, N is an alkaline earth metallic element and an alkaline rare earth element (excluding Ce and Zr), 0.65<1-(a+b)<=0.90, 0.10<=a<0.35, 0<=b<=0.20 and; C is an oxygen loss to be determined by N) and a compound oxide B represented by formula II (wherein, M is an alkaline earth metal element and an alkaline rare earth element (excepting Ce and Zr), 0.35<=1-(x+y)<=0.80, 0.20<=x<=0.65, 0<=y<=0.20 and: Z is an oxygen loss to be determined by M), is formed on a heat-resistant support carrier. In addition, the weight of Rh carried by the compound oxide A is set not less than the weight of Rh carried by the compound oxide B. |
