Exhaust Gas Purification Catalyst

An exhaust gas purification catalyst placed in an exhaust path connected to an internal combustion engine and purifying exhaust gas discharged from the internal combustion engine, the exhaust gas purification catalyst comprising:

• a substrate that has a plurality of cells and a partition wall separating the plurality of cells;
• and
• a catalyst layer that is a porous layer provided on a surface of the partition wall and has an OSC material including CeO2 and a catalytic metal, wherein
• the catalyst layer has a laminated structure of at least two layers, with a lower catalyst layer thereof being closer to the surface of the partition wall and an upper catalyst layer thereof being relatively farther from the surface of the partition wall,
• the lower catalyst layer has
• a lower-layer front portion A that extends from an upstream end of the substrate in an exhaust gas flow direction toward a downstream side, has a CeO2 content ACeO2 of 0 g/L to 15 g/L, and includes Pd as the catalytic metal, and
• a lower-layer rear portion B that extends from a downstream end of the substrate in the exhaust gas flow direction toward an upstream side, has a CeO2 content BCeO2 of 20 g/L to 63 g/L, and includes at least one of Pd and Pt as the catalytic metal;
• and
• the upper catalyst layer has
• an upper-layer front portion C that extends from the upstream end of the substrate in the exhaust gas flow direction toward the downstream side, has a CeO2 content CCeO2 of 1 g/L to 7 g/L, and includes Rh as the catalytic metal, and
• an upper-layer rear portion D that extends from the downstream end of the substrate in the exhaust gas flow direction toward the upstream side, has a CeO2 content DCeO2 of 2 g/L to 8 g/L, and includes Rh as the catalytic metal, and
• the catalyst layer has a NOX storage region including Pt together with a NOX storage material, the NOX storage region being formed closer to a partition wall side than the upper catalyst layer.