Exhaust gas catalyst and exhaust gas processing apparatus using same

摘要

An exhaust gas catalyst where the catalyst efficiency is improved by enhancing diffusion of the exhaust gas in a catalyst layer. An exhaust gas catalyst comprises at least a carrier and a plurality of layers formed on the carrier. At least one of the layers has pores therein, and at least one other layer has pores therein and contains, as catalyst components, a noble metal, alumina and a complex oxide mainly containing ceria, zirconia and one or more rare earth elements other than cerium.

主权项

1. An exhaust gas catalyst comprising at least a support and multiple layers formed on the support, wherein
at least one of the multiple layers has voids therein formed via a forming agent; and the at least one of the multiple layers having voids therein comprises, as catalytic components, a noble metal, alumina, and one or more composite oxides comprising, as main components, ceria, zirconia and one or more rare earth elements except for ceria, wherein the average diameter of the voids ranges from not less than 0.2 μm to not more than 500 μm and the one or more composite oxides has a specific surface area, after a heat treatment at 1000° C. for 2 hours, of not less than 40 m2/g.