| abstract |
The invention provides a catalyst article including a substrate underlying a multi-layer catalyst composition and a multi-layer catalyst composition comprising a first layer and a second layer, the first layer positioned between the substrate and the second layer, wherein the first layer comprises a first porous refractory oxide material impregnated with at least one base metal component and the second layer comprises a second porous refractory oxide material impregnated with at least one platinum group metal. Either the second porous refractory oxide material is a porous refractory oxide material other than alumina or the catalyst composition further comprises an intermediate layer between the first layer and the second layer, the intermediate layer comprising a refractory oxide material other than alumina. Methods of making and using the catalyst article are also provided, as well as emission treatment systems comprising the catalyst article. |