Patent ID: 8513155

Claim:
A lean NO X trap for incorporation into an exhaust aftertreatment system, the lean NO X trap comprising: a diesel particulate trap comprising a monolithic honeycomb structure having a plurality of flow-through cells, and a catalyst material carried by the monolithic honeycomb structure, the catalyst being constructed and arranged to remove nitrogen oxide gases (NO X ) contained in a flow of engine-out exhaust emitted from a lean-burn engine that is supplied with a mixture of air and fuel, the catalyst material comprising a NO X oxidation catalyst that comprises a perovskite compound for catalytically oxidizing NO to NO 2 when the mixture of air and fuel is lean, wherein the catalyst material further comprises a carrier material on which the NO X oxidation catalyst is dispersed, wherein the catalyst material further comprises a NO X storage catalyst that stores NO 2 as a nitrate species when the mixture of air and fuel is lean and releases NO X gases when the mixture of air and fuel is rich, a NO X reduction catalyst that reduces NO X gases to N 2 when the mixture of air and fuel is rich, and palladium, and wherein the NO X storage catalyst, the NO X reduction catalyst, and the palladium are dispersed on the carrier material with the NO X oxidation catalyst.