Exhaust gas purification catalyst and production method thereof

摘要

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.

主权项

1. An exhaust gas purification catalyst comprising:
a lower catalytic layer having catalytic ability to oxidize HC and CO on a substrate; and an upper catalytic layer having catalytic ability to reduce NOx on top of, or above, the lower catalytic layer, wherein the lower catalytic layer contains Pt and Pd acting as catalytic metals, zeolite, Ce-containing oxide, and activated alumina, the upper catalytic layer contains activated alumina loading an Rh-doped Ce-containing oxide and an alkali earth metal acting as an NOx storage material, the lower catalytic layer includes a first oxidation catalyst layer containing activated alumina loading Pt and Pd and a Ce-containing oxide loading Pt and Pd, and a second oxidation catalyst layer containing zeolite loading Pt and Pd, and the second oxidation catalyst layer is disposed on the first oxidation catalyst layer.