| CPC B01J 23/464 (2013.01) [B01J 23/42 (2013.01); B01J 23/44 (2013.01); B01J 35/19 (2024.01); F01N 3/20 (2013.01); F01N 2570/10 (2013.01); F01N 2570/12 (2013.01); F01N 2570/14 (2013.01)] | 6 Claims |
|
1. A method for purifying an exhaust gas discharged from the internal combustion engine and including methane, the method comprising:
disposing an exhaust gas purification catalyst in an exhaust path of an internal combustion engine, and
purifying an exhaust gas discharged from the internal combustion engine and including methane by the exhaust gas purification catalyst, wherein
the exhaust gas purification catalyst comprising:
a substrate that divides cells through which an exhaust gas flows; and
a catalyst layer that is provided on a surface of the substrate,
wherein the catalyst layer includes
a palladium layer containing palladium that extends from a first end part which is an end part on a side of the cells into which an exhaust gas flows to a second end part which is an end part on a side of the cells from which an exhaust gas flows out,
a platinum layer containing platinum that extends from the second end part to the first end part, and
a rhodium layer containing rhodium that is laminated on both the palladium layer and the platinum layer,
wherein a ratio A/B of a molar amount A of the palladium contained per unit volume of the substrate of a portion in which the palladium layer is provided in a length direction from the first end part to the second end part of the substrate to a molar amount B of the platinum contained per unit volume of the substrate of a portion in which the platinum layer is provided in the length direction is 1.2 or more and 2.8 or less.
|