EXHAUST GAS PURIFICATION CATALYST

摘要

PROBLEM TO BE SOLVED: To provide an exhaust gas purification catalyst capable of suppressing deterioration in exhaust gas purification performance even under an environment exposed to a high-temperature exhaust gas.SOLUTION: There is provided an NOx purification catalyst 130 obtained by carrying a catalyst coat layer 136 having purification performance for exhaust gas on a cell wall 131, wherein the catalyst coat layer 136 has a purification accelerating layer 134 which is formed on the surface of the cell wall 131 and contains at least a silver-carrying alumina and a heat-resistant layer 135 which is formed on the surface of the opposite cell wall side of the purification accelerating layer 134 and is a silver-carrying ceria and the average particle diameter of silver particles in the heat-resistant layer 135 is larger than the average particle diameter of silver particles in the purification accelerating layer 134.SELECTED DRAWING: Figure 3