| abstract |
A wall-flow filter for filtering particulate matter from a flowing exhaust gas comprises a catalyst for catalysing both the conversion of solid carbon in the particulate matter by oxygen and the selective reduction of oxides of nitrogen in the exhaust gas with a nitrogenous reductant, which catalyst comprising optionally stabilised ceria and at least one metal selected from (i) tungsten and (ii) both tungsten and iron. The catalyst may be coated on an inert filter substrate. The solid body may consist of 10-90% by weight of a binder/matrix component and 5-80% by weight of optionally stabilised ceria. A method of production for both catalysts and their use in the conversion of nitrogen oxides in exhaust gas systems is also provided. |