GASOLINE ENGINE EXHAUST GAS PURIFICATION THREE-WAY CATALYST

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The present invention relates to : an exhaust gas purification catalyst which is a relatively inexpensive three-way catalyst containing a noble metal component and is resistant to sintering of the noble metal even at high temperatures, can purify carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NOx), and is particularly excellent in purifying nitrogen oxide; and an exhaust gas purification method. The exhaust gas purification catalyst is a gasoline engine exhaust gas purification three-way catalyst characterized in that a catalyst composition is coated in at least two layers on a support comprising a honeycomb structure, a Pd-supporting heat-resistant inorganic oxide and an La-containing oxide are contained in an upper layer, an Rh-supporting heat-resistant inorganic oxide is contained in a lower layer, and the content of each of the La, Ce, and Ba is as follows per unit volume for the honeycomb structure : the La content is 9.6 to 23 g/L as La2O3; the Ce content is 5 to 20 g/L as CeO2; and the Ba content is not more than 1.2 g/L as BaO.