Patent ID: 7846863

Claim:
An exhaust gas purifying catalyst comprising: a substrate having a through hole penetrating the substrate in an axial direction; and the through hole forms a passage for an exhaust gas, an upstream catalyst coating layer being formed on an internal surface of an area A located on an upstream portion of the passage, with respect to a flow direction of the exhaust gas through the through hole, and the upstream catalyst coating layer consisting of: a precious metal, barium (Ba) and lanthanum (La); and at least one of: a Zr oxide, a mixture of Zr oxide and a ZrCe mixed oxide, a mixture of Zr oxide and Ce oxide, and a mixture of Zr oxide, a Ce oxide and ZrCe mixed oxide, and the upstream catalyst coating layer contains at least Zr oxide in which an oxide equivalent weight of Zr, contained in area A, is within a range of 51 to 100 wt % of an oxide equivalent weight of Zr and Ce contained in the area A, and a downstream catalyst coating layer formed on an internal surface of an area B located on a downstream portion of the passage with respect to the flow direction of the exhaust gas through the through hole, the downstream catalyst coating layer consisting of: a precious metal, barium (Ba) and lanthanum (La); and at least one of: a Ce oxide, a ZrCe mixed oxide; and a mixture of Ce oxide and a ZrCe mixed oxide; and the downstream catalyst coating layer contains at least one of Ce oxide and ZrCe mixed oxide in which an oxide equivalent weight of Ce, contained in area B, is within a range of 58 to 100 wt % of an oxide equivalent weight of Zr and Ce, contained in the area B.