Patent ID: 7229597

Claim:
An emission treatment system for treatment of an exhaust stream comprising NOx and particulate matter, the emission treatment system comprising: a) an oxidation catalyst; b) an injector in fluid communication with and downstream of the oxidation catalyst, wherein the injector periodically meters ammonia or an ammonia precursor into the exhaust stream; and c) a wall flow monolith in fluid communication with and downstream of the injector, wherein the wall flow monolith has a plurality of longitudinally extending passages formed by longitudinally extending walls bounding and defining said passages, wherein the passages comprise inlet passages having an open inlet end and a closed outlet end, and outlet passages having a closed inlet end and an open outlet end, wherein the wall flow monolith comprises an SCR catalyst composition that permeates the walls at a concentration of at least 1.3 g/in 3 ; wherein the wall flow monolith has a wall porosity of at least 50% with an average pore size of at least 5 microns.