US Patent 9550176 Exhaust gas purification catalyst and production method thereof

This catalyst includes a lower catalytic layer 2 having catalytic ability to oxidize HC and CO and an upper catalytic layer 3 having catalytic ability to reduce NOx. The lower catalytic layer 2 contains Pt and Pd acting as catalytic metals, zeolite, a Ce-containing oxide, and activated alumina, and the upper catalytic layer 3 contains activated alumina loading an Rh-doped Ce-containing oxide and an NOx storage material.