Exhaust gas-purifying catalyst and method of manufacturing the same

摘要

An exhaust gas-purifying catalyst whose activity is less prone to be decreased even in the case where used in a high-temperature atmosphere containing oxygen at a high concentration can be realized. The catalytic layer of the catalyst includes an oxide particle, a simple oxide of alkaline-earth element or rare-earth element, and alumina and/or aluminum hydroxide. The oxide particle contains an oxide of rare-earth element and/or zirconium, a composite oxide and a precious metal. The composite oxide contains an alkaline-earth element and at least one of the rare-earth element and zirconium. The composite oxide and a part of the precious metal form a solid solution.

主权项

1. An exhaust gas-purifying catalyst comprising a substrate and a catalytic layer supported by the substrate, the catalytic layer comprising:
an oxide particle containing
an oxide of at least one of cerium and zirconium,a composite oxide containing barium, cerium and zirconium, anda precious metal, the composite oxide and a part of the precious metal forming a solid solution; a particle of a simple oxide of magnesium, supported by the oxide particle; and a particle of alumina and/or aluminum hydroxide, supported by the oxide particle,
wherein an atomic ratio of barium with respect to the sum of cerium and zirconium in the oxide particle is within a range of 0.1 atomic % to 100 atomic % and wherein an atomic ratio of the magnesium to the aluminum falls within a range of 0.05 to 2.0.