Patent attributes
A substrate (11) of an exhaust gas purification catalyst (10) includes inflow-side cells (21), outflow-side cells (22), and porous partition walls (23), each porous partition wall separating the cells (21, 22) from each other. A first catalyst portions (14) is provided at least on a portion of a side of the partition wall (23) that faces the inflow-side cell (21), the portion being located on an upstream side in an exhaust gas flow direction, and a second catalyst portion (15) is provided at least on a portion of a side of the partition wall that faces the outflow-side cell, the portion being located on a downstream side in the exhaust gas flow direction. A first pore volume is greater than a second pore volume, where the first pore volume is a pore volume of pores with a pore size of 10 μm to 18 μm, as measured on the first catalyst portions (14) and the partition walls (23) within a region where the first catalyst portions (14) are provided, and the second pore volume is a pore volume of pores with a pore size of 10 μm to 18 μm, as measured on the second catalyst portions (15) and the partition walls (23) within a region where the second catalyst portions (15) are provided. The first catalyst portion (14) exhibits the peak top of the pore size at between 20 nm and 500 nm.
