Patent ID: 8544260

Claim:
An emissions treatment system for treating an engine exhaust gas stream containing an initial NO x concentration and particulate matter, the system providing a system back pressure and a system NO x conversion, the system comprising: a reductant injector; a honeycomb wall flow filter comprising a first SCR catalyst effective for NO x conversion disposed downstream of the reductant injector and having a loading in the range of about 0.1 g/in 3 and 2.5 g/in 3 with no intervening SCR catalysts disposed between the engine and the honeycomb wall flow filter; and a flow through substrate loaded with a second SCR catalyst effective for NO x conversion disposed downstream of the honeycomb wall flow filter, the honeycomb wall flow filter catalyst loading effective to provide a system back pressure that is less than about 25% greater than system back pressure associated with a similar system including a filter not loaded with catalyst and the system NO x conversion is in the range of about 50% and 100%.