The invention relates to a catalytic filter comprising a porous matrix made from an inorganic material in the form of grains which are interconnected such as to form cavities therebetween, with an open porosity of between 30 and 60 % and a median pore diameter of between 5 and 40 μm. The filter is characterised in that at least part of the surface of the grains, and optionally the grain boundaries, of the inorganic material is covered with a texturing material, said texturisation consisting of surface irregularities having dimensions of between 10 nm and 5 micrometres, and in that the catalytic coating at least partially covers the texturing material and, optionally, the grains of the inorganic material.