Patent ID: 8247339

Claim:
A ceramic catalyst body comprising a ceramic carrier made of cordierite which supports catalyst, the ceramic carrier comprising a plurality of cells surrounded by a plurality of cell walls arranged in a honeycomb shape, wherein the ceramic catalyst body has its separation ratio H of catalyst expressed by the following formula (1), H= 217.254+(−0.167)× T+ 0.345 ×D+ 28.731 ×ΔCTE− 3.343 ×S (1), where Δ CTE (×10 −6 /° C.) is a difference=C 1 −C 2 between a thermal expansion coefficient C 1 of the ceramic catalyst body and a thermal expansion coefficient C 2 of the ceramic carrier, T(K) is an internal temperature of the ceramic carrier, D(cc/g) is a amount of fine pores of not more than 2 μm in the ceramic carrier, and S(%) is a surface porosity indicating the ratio of an area of opening parts of the fine pores formed on a surface of the ceramic carrier to the surface area of the ceramic carrier, wherein the ceramic catalyst body has an entered amount of the catalyst of not more than 25%, where the entered amount of the catalyst indicates a ratio of an area of a catalyst part, where the catalyst has entered into the inside of the ceramic carrier in a particular area on a cross section of the ceramic carrier, to said particular area, and the separation ratio H is not more than 35%.