Oxidation Catalyst With Low CO and HC Light-Off and Systems and Methods

Abstract

An oxidation catalyst for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO) and the reduction of nitrogen oxides (NOx) from a diesel engine and methods of exhaust gas treatment are disclosed. More particularly, a washcoat composition is disclosed comprising at least two washcoat layers, a first washcoat comprising palladium supported on ceria-zirconia and ceria-zirconia-alumina and a second washcoat containing one or more of platinum and palladium and one or more hydrocarbon storage components. An undercoat may also be included in the catalyst. Also disclosed are method of exhaust gas treatment and diesel exhaust gas treatment systems that include the oxidation catalyst and a downstream soot filter.

Dependencies are inferred from the claim text.