Catalytic wall flow filter

A method for the manufacture of a catalytic wall-flow filter, the method comprising:

• (a) providing a wall-flow filter substrate comprising porous walls and having a first face and a second face defining a longitudinal direction therebetween and first and second pluralities of channels extending in the longitudinal direction, wherein the first plurality of channels is open at the first face and closed at the second face, and wherein the second plurality of channels is open at the second face and closed at the first face;
• (b) applying a first coating material in the first plurality of channels from the first face;
• (c) applying a second coating material in the second plurality of channels from the second face, the second coating comprising a PGM selected from the group consisting of palladium and platinum and mixtures thereof, an oxygen storage capacity (OSC) material, and an inorganic support, wherein the second coating material is free of rhodium;
• (d) calcining a coated wall-flow filter substrate obtained from steps (b) and (c) to produce the catalytic wall-flow filter.