EXHAUST GAS PURIFICATION CATALYST

摘要

PURPOSE:To obtain an exhaust gas purification catalyst which prevents the thermal deterioration of precious metal and has an improved heat resistance by fixing the catalytic precious metal component of a first coat layer with lanthanum oxide and barium oxide particles. CONSTITUTION:An exhaust gas purification catalyst is provided on a catalyst carrier 2 with a first coat layer 3 as alumina coat layer and a second coat layer 4 consisting mainly of cerium oxide built up in layers in that order. A catalytic precious metal component is contained in the activated alumina of this first coat layer 3 and this catalytic precious metal component is fixed with at least one kind of lanthanum oxide and barium oxide particles in a dispersed state. This method effectively controls the sintering of the catalytic precious metal component as well as interactions between the cetalytic precious metal component and the alumina of the first coat layer. Therefore, heat resistance is improved.