Catalyzed particulate filter

A particulate filter, which comprises;

• a substrate, comprising a plurality of porous walls extending longitudinally to form a plurality of parallel channels extending from an inlet end to an outlet end, wherein a quantity of the channels are inlet channels that are open at the inlet end and closed at the outlet end, and a quantity of channels are outlet channels that are closed at the inlet end and open at the outlet end;
• an in-wall TWC coating in the inlet channels and the outlet channels, comprising a platinum group metal component, an alumina-based refractory metal oxide and an oxygen storage component, wherein the in-wall TWC coating has a weight ratio of the alumina-based refractory metal oxide to the oxygen storage component in the range of 1:20 to 1:3, and wherein the in-wall TWC coating is free of any individual zirconium species and barium species;
• and,
• optionally, an on-wall layer of inorganic particles in the inlet channels and/or outlet channels, wherein the inorganic particles comprise one or more non-PGM components selected from alumina, zirconia, ceria, silica, titania, magnesium oxide, manganese oxide, zinc oxide, rare earth metal oxide other than ceria, or any composite oxides thereof.