SCR EXHAUST AFTERTREATMENT APPARATUS, SYSTEM AND METHODS INCLUDING MULTIPLE WASHCOAT FORMULATIONS

摘要

Unique SCR catalyst including multiple washcoat formulations with differing performance characteristics are disclosed. One exemplary embodiment is an apparatus including a catalyst substrate defining a plurality of flow channels leading from an inlet to an outlet, a first washcoat composition distributed over a first portion of the flow channels, and a second washcoat composition distributed over a second portion of the flow channels. The first washcoat composition has a lower ammonia storage density than the second washcoat composition.

主权项

1. An exhaust aftertreatment system comprising:
an inlet structured to receive a flow of exhaust produced by an engine; an injector positioned downstream from the inlet and structured to inject reductant into the flow of exhaust; and an SCRF catalyst positioned downstream from the injector, the SCRF catalyst comprising a particulate filter substrate including a plurality of flow channels, a first washcoat composition deposited on first surfaces of the flow channels in a first region along the length of the substrate, and a second washcoat composition deposited on second surfaces of the flow channels in a second region along the length of the substrate, the second region being downstream from the first region, the first washcoat composition having a lower NH3 storage density than the second washcoat composition.