EXHAUST GAS PURIFICATION CATALYST

摘要

PROBLEM TO BE SOLVED: To provide an exhaust gas purification catalyst which has high initial performance and maintains exhaust gas purification performance even after endurance.SOLUTION: An exhaust gas purification catalyst includes a catalyst base material and a catalyst coat layer formed on the catalyst base material. Alloy particles formed of (1) a first noble metal selected from a group of palladium and platinum, and (2) a second noble metal different from the first noble metal and selected from a group of platinum and rhodium are supported on the catalyst coat layer. When a standard deviation calculated from an average value of a weight ratio between the first noble metal and the second noble metal supported per unit area of the catalyst coat layer is divided by the average value, the standard deviation is within a range of 50% or less of the average value.