PURPOSE: To obtain a catalyst of high activity with little thermal deterioration and large specific surface area in which catalytic material can be highly dispersed by providing a catalyst carrier layer of specified compsn. carrying a noble metal catalytic component on a ceramic formed body.
CONSTITUTION: The catalyst is obtained by providing a catalyst carrier layer which carries a noble metal catalytic component on a ceramic formed body. This catalyst carrier layer is formed on the ceramic formed body from a mixture liquid of alumina sol and silica sol as the starting material, and then at least one noble metal selected from platinum, palladium and rhodium is deposited thereon. By using a gel-type alumina sol and silica sol as the starting material, alumina fine particles (δ-Al2O3 determined by X-ray analysis) are grown, and by adding silica sol (SiO2), a catalyst carrier layer having good stability at high temp. can be obtd. Moreover, since the starting material is liquid, the catalyst carrier layer can be easily formed by dipping a ceramic formed body and then calcining.
YAMASHITA YOSHIHARU
AWANO JUNJIRO
