Layered catalyst composite

Abstract

A catalyst composition and layered catalyst composite of the type generally referred to as a three-way conversion catalyst having the capability of substantially simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides. The catalyst composition comprises at least two supports, at least one first precious metal component. There is at least one lanthana stabilized alumina support, and at least one refractory oxide unstabilized support. The composition further comprises at least one precious metal component located on the lanthana stabilized alumina support and the unstabilized support. There is an oxygen storage composition comprising, 40 to 80 weight percent of a diluent component, 10 to 60 weight percent of a cerium component, 1 to 15 weight percent of a neodymium component, and 1 to 15 weight percent of a praseodymium component. The composition also comprises at least one alkaline earth metal stabilizer; and a zirconium component.

Dependencies are inferred from the claim text.