PURPOSE: To eliminate the peeling of a catalyst carrying layer from a metallic carrier by forming a lanthanum oxide-contg. film and a carrying layer of alumina on the carrier made of Cr-Fe-Al ferrite stainless steel, and depositing a metallic catalyst on the carrier layer.
CONSTITUTION: Lanthanum oxide is thermally sprayed on the surface of the thin sheet 1 made of Cr-Fe-Al ferrite stainless steel to form an oxide coated film 4, and a monolithic carrier substrate is formed. then a slurry contg. activated alumina is deposited on the surface of the carrier substrate, then baking is applied, and the carrying layer 5 consisting essentially of activated alumina is formed on the oxide coated film. A catalytic metal is further deposited on the carrying layer to produce the monolithic catalyst for purifying exhaust gas. In the thermal spraying of lanthanum oxide, 0.25W24 millimols lanthanum per liter of the monolithic catalyst is preferably sprayed.
MATSUMOTO SHINICHI
MIYOSHI NAOTO
