SELECTIVE CATALYTIC REDUCTION WALL FLOW FILTER INCOPORATING A VANADATE

摘要

A filter incorporates a catalyst for the Selective Catalytic Reduction (SCR) of NOx gases and removal of particulate matter from the exhaust gas of a lean burn combustion engine, wherein the catalyst includes a vanadate component having an alkaline earth metal, a transition metal, a rare earth metal, or combinations thereof. The vanadate component may be iron vanadate. The filter includes a supported vanadate component disposed on a wall-flow filter. The method of making the filter includes applying an aqueous mixture of the supported vanadate component as a washcoat on the wall-flow filter or extruding a composition containing the supported vanadate component. The method of treating exhaust gases from an engine includes contacting the exhaust gas with the catalyst including the vanadate component.

主权项

1. A filter comprising:
a substrate in the form of a wall-flow filter and a catalyst disposed on said substrate, said catalyst comprising a support and a vanadate component, said vanadate component having a structure defined by the following formula:
(AX)(TY)(RZ)VO4 wherein “A” is an alkaline earth metal and “X” is the molar ratio of the alkaline earth metal to vanadate;“T” is a transition metal and “Y” is the molar ratio of the transition metal to vanadate;“R” is a rare earth metal and “Z” is the molar ratio of the rare earth metal to vanadate; and0≦X≦1; 0≦Y≦1; 0≦Z≦1; and X+Y+Z=1; and wherein said vanadate component is carried on said support.