Patent ID: 7749472

Claim:
An automobile exhaust gas treatment catalyst consisting of: (a) a substrate coated with at least two washcoat layers containing one or more precious metal components, wherein at least one washcoat layer optionally comprises an oxygen storage component; and (b) an overcoat layer comprising a porous refractory oxide, and one or more base metal oxides, wherein when said base metal oxide is lanthanum oxide said lanthanum oxide is present in an amount of no more than 0.2 g/in 3 and wherein said overcoat layer is devoid of precious metals and optionally comprises an oxygen storage component, and wherein either: i) said at least two washcoat layers containing one or more precious metal components are contiguous to one another and are coated with said overcoat layer, or ii) said overcoat layer is placed between a pair of the at least two washcoat layers containing one or more precious metal components, said pair of washcoat layers comprising a bottom washcoat layer and a top washcoat layer and wherein said overcoat layer is coated over said bottom washcoat layer.