Layered automotive catalytic composite

Abstract

This invention relates to a catalytic composite for treating an exhaust gas comprising a first support which is refractory inorganic oxide having dispersed thereon at least one noble metal component and having dispersed immediately thereon an overlayer comprising at least one oxygen storage component and optionally a second support which is a refractory inorganic oxide. The first support may be selected from the group consisting of alumina, silica, titania, zirconia and aluminosilicates with alumina being preferred. Additionally, the noble metal component may be selected from the group consisting of platinum, palladium, rhodium, ruthenium and iridium. The oxygen storage component is an oxide of a metal which includes cerium, iron, nickel, cobalt lanthanum, neodymium, praesodymium, etc. and mixtures thereof. Cerium oxide is a preferred oxygen storage component. Finally, the second support may be selected from the group consisting of alumina, silica, titania, zirconia and aluminosilicates, with alumina preferred. This invention also relates to a process for minimizing the content of hydrogen sulfide in an automotive exhaust gas which comprises contacting said exhaust gas with a catalyst composite comprising a first support which is a refractory inorganic oxide having dispersed thereon at least one noble metal component and having dispersed immediately thereon an overlayer comprising at least one oxygen storage component and optionally a second support which is refractory inorganic oxide.

Dependencies are inferred from the claim text.