Patent ID: 7608561

Claim:
An exhaust gas purifying catalyst comprising: a honeycomb substrate disposed in an exhaust passage for an engine; and a catalytic layer formed on a cell wall of said substrate, said catalytic layer including a mixed oxide which contains Ce (cerium) and Zr (zirconium), and retains a catalytic noble metal in such a manner that said noble metal atoms are located at crystal lattice points or between the lattice points of the mixed oxide, wherein said mixed oxide includes a first mixed oxide containing CeO 2 in a mass greater than that of ZrO 2 , and a second mixed oxide containing ZrO 2 in a mass greater than that of CeO 2 , wherein said first mixed oxide contains CeO 2 in 65 mass % or more with respect to a total mass of CeO 2 , and ZrO 2 ; said second mixed oxide contains ZrO 2 in 65 mass % or more with respect to a total mass of CeO 2 and ZrO 2 , and wherein said catalytic layer comprises a plurality of layers having a laminated structure, at least one of said layers containing said first mixed oxide, and at least one of the remaining layers containing said second mixed oxide.