| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust gas purification catalyst which exerts a sufficient oxidation activity on e.g. carbon monoxide, hydrocarbons and nitrogen monoxide even at low temperatures.SOLUTION: An exhaust gas purification catalyst includes an alumina support, a silica layer formed on the surface of the alumina support and active metal particles composed of platinum and palladium supported in the silica layer. The ratio of fine particles of particle sizes of 2.0 nm or smaller in active metal particles is 50% or higher, in terms of the number of particles, relative to all active metal particles, and the ratio of alloy fine particles of a palladium content of 10-90 at% in the fine particles is 50%, in terms of the number of particles, relative to all fine particles. |
