ENGINE EXHAUST CATALYSTS DOPED WITH BISMUTH OR MANGANESE

摘要

An emission control catalyst is doped with bismuth, manganese, or bismuth and manganese. The doped catalyst may be a palladium-gold catalyst or a platinum-based catalyst, or both. The doped palladium-gold catalyst and the doped platinum-based catalyst may be contained in a single washcoat layer or in different washcoat layers of a multi-brick, multi-zoned, or multi-layered emission control system. In all embodiments, zeolite may be added as a hydrocarbon absorbing component.