Patent ID: 7481983

Claim:
An emissions treatment system, comprising: a) an injector for periodically metering ammonia or an ammonia precursor into an exhaust stream; b) a first substrate comprising a first SCR catalyst composition, downstream of the injector; wherein the first substrate has an inlet end, an outlet end, a length extending between the inlet end to the outlet end, wall elements and a plurality of passages defined by the wall elements; wherein the first SCR catalyst composition is disposed on the wall elements from the inlet end toward the outlet end to a length that is less than the substrate's axial length to form an inlet zone; an NH 3 destruction catalyst composition comprising a platinum group metal component dispersed on a refractory metal oxide, wherein the NH 3 destruction catalyst composition is disposed on the wall elements from the outlet end toward the inlet end to a length that is less than the substrate's axial length to form an outlet zone; and wherein there is from 0.1 to 10 g/ft 3 of platinum group metal component in the outlet zone.