Catalyst assembly for treating engine exhaust

摘要

According to one aspect of the present invention, a catalyst assembly is provided for treating an exhaust from an engine. In one embodiment, the catalyst assembly includes a first catalyst material catalytically active at a first temperature and loaded at a first catalyst material loading, the first catalyst material including a first base metal loading, and a second catalyst material catalytically active at a second temperature lower than the first temperature and loaded at a second catalyst material loading, the second catalyst material including a second base metal loading, wherein the second base metal loading is higher than the first base metal loading.

主权项

1. An SCR catalyst assembly comprising:
a substrate; an upstream catalyst material coated onto the substrate, including a first base metal of copper or iron loaded in a first zeolite at an upstream loading of 0 to 3.5 g/l and having a NOx conversion activity in a first temperature range of 150° C. to 500° C.; and a downstream catalyst material coated onto the substrate downstream of the upstream catalyst material, including a second base metal of copper or iron loaded in a second zeolite at a downstream loading of 1.5 to 9.5 g/l and having a NOx conversion activity in a second temperature range of 450° C. to 700° C.