Patent ID: 7097817

Claim:
A method for treating soot-containing exhaust gas with a wall-flow filter comprising the steps of: (i) passing an exhaust gas over an oxidation catalyst disposed on a gas-impermeable zone along the wall-flow filter to convert an amount of NO in the exhaust gas to NO 2 , wherein the wall-flow filter comprises a honeycomb arrangement defining: (a) a plurality of first channels plugged at an upstream end, and (b) a plurality of second channels not plugged at an upstream end, but plugged at a downstream end; (ii) thereafter, trapping soot from the exhaust gas in a catalyst-free gas-impermeable zone disposed along the plurality of second channels; and (iii) continuously combusting the trapped soot generated from step (ii) with the NO 2 produced from step (i), wherein the amount of NO 2 generated from step (i) is sufficient to enable combustion of the trapped soot in the catalyst-free gas-impermeable zone disposed along the plurality of second channels plugged at the downstream end at a temperature less than 400° C.