Patent attributes
An exhaust gas purifying catalyst having a good ignition performance is provided. The exhaust gas purifying catalyst 1 includes a catalyst substrate 3 and a catalyst coating layer 5 which contains a noble metal and a refractory inorganic oxide and is formed on the catalyst substrate. The exhaust gas purifying catalyst is characterized in that the catalyst coating layer 5 includes an upstream portion 11 located upstream and a downstream portion 13 located downstream in a flow direction of an exhaust gas. The upstream portion 11 has a layered structure including an upstream portion inside layer 17 and an upstream portion outside layer 15. The upstream portion inside layer contains a cerium-zirconium composite oxide in which a relative proportion of CeO2 is 50 to 95 wt %, as the refractory inorganic oxide, and the upstream portion outside layer 15 and the downstream portion 13 contain a cerium-zirconium composite oxide in which a relative proportion of ZrO2 is 50 to 95 wt %, as the refractory inorganic oxide.
