Method for improving the thermal shock resistance of a washcoated body

摘要

A method for producing a thermally shock resistant washcoated substrate involves introducing a buffer solution into the microcracks, and optionally the micropores of a porous sintered body, the pH of the buffer solution being at a predetermined value to result in the formation of a gel on contact of the buffer solution with the slurry which is to be subsequently applied, contacting the body with a washcoating slurry to form a gel at the interface of the buffer solution and slurry. Formation of the gel prevents the slurry from entering the microcracks. The body is then calcined at a temperature and for a time sufficient to form the washcoated substrate.