Patent ID: 7258825

Claim:
A process for making an intermediate product for producing a filter comprising: preparing a ceramic foam by preparing a perform of polymeric foam material, impregnating the perform with a ceramic-powder slurry, and subjecting the impregnated perform to a thermal cycle of sintering, wherein the ceramic-material powder slurry is selected from the group consisting of mullite (3Al 2 O 3 -2SiO 2 ) powder, alumina (Al 2 O 3 ) powder, and zirconia (ZrO 2 ) powder, and mixtures thereof, and wherein the ceramic-material powder slurry has a purity of over 97%, mean (number based) particle size of less than 2 μm, and a specific B.E.T. surface at least greater than 5 m 2 /g, and depositing an oxidizing catalyst on the ceramic foam to produce a filter.