| abstract |
In the case of an exhaust gas purification catalyst in which alumina, an oxygen storage material and a catalyst metal are contained in a catalyst layer, when the heat resistance of alumina or the heat resistance of a composite oxide as an oxygen storage material is not sufficient, Purification performance decreases due to aggregation and sintering. When the alumina and the composite oxide are in a physically mixed state or have a composite structure in which oxide particles are dispersed with each other, the amount of the composite oxide on the alumina surface decreases, and the composite oxide surface Since the amount of the catalyst metal is insufficient and the oxygen storage / release capability cannot be ensured, high purification performance cannot be ensured. An exhaust gas purification catalyst in which a composite oxide containing at least Ce, Zr, and La as an oxygen storage material is supported on alumina containing La has improved high-temperature purification performance and improved light-off temperature. The [Selection] Figure 3 |