Abstract: The present disclosure provides the exhaust gas purification catalyst with the improved purification performance under the high Ga condition and the transient state in which an A/F repeats rich and lean phases. The present disclosure relates to an exhaust gas purification catalyst comprising a catalyst coating layer on a substrate, the catalyst coating layer containing a noble metal, a composite oxide containing cerium oxide and zirconium oxide, and a composite oxide containing aluminum oxide, wherein in the catalyst coating layer: an average thickness of the coating layer is in a range from 20 ?m to 100 ?m; a porosity measured by a weight-in-water method is in a range from 50% by volume to 80% by volume; and high-aspect-ratio pores having an aspect ratio of 5 or more account for 0.

Abstract: An catalyst for purifying exhaust gas comprising an OCS material that has sufficient heat resistance and achieves a favorable balance between the oxygen storage volume and the oxygen absorption/release rate includes an catalyst for purifying exhaust, which has a substrate and a catalyst coating layer formed on the substrate, wherein the catalyst coating layer comprises a ceria-zirconia-based composite oxide having a pyrochlore structure in an amount of 5 to 100 g/L based on the volume of the substrate, the ceria-zirconia-based composite oxide has a secondary particle size (D50) of 3 ?m to 7 ?m, and the ceria-zirconia-based composite oxide optionally contains praseodymium.

Abstract: An catalyst for purifying exhaust gas comprising an OCS material that has sufficient heat resistance and achieves a favorable balance between the oxygen storage volume and the oxygen absorption/release rate includes an catalyst for purifying exhaust, which has a substrate and a catalyst coating layer formed on the substrate, wherein the catalyst coating layer comprises a ceria-zirconia-based composite oxide having a pyrochlore structure in an amount of 5 to 100 g/L based on the volume of the substrate, the ceria-zirconia-based composite oxide has a secondary particle size (D50) of 3 ?m to 7 ?m, and the ceria-zirconia-based composite oxide optionally contains praseodymium.