PURPOSE: To improve the heat resistance, activity and durability of a carrier, by molding a catalyst carrier from a composition prepared by compounding 0.5W15pts.wt. of silicon oxide and 1W40wt% of lanthanum oxide with 100pts.wt. of aluminum oxide.

CONSTITUTION: An aluminum stock material such as alumina or aluminum hydroxide, a silicon oxide stock material such as colloidal silica and a lanthanum oxide stock material such as lanthanum nitrate or lanthanum chloride are mixed and baked to form a catalyst carrier consisting of 100pts.wt. of aluminum oxide, 0.5W15pts.wt. of silicon oxide and 1W40pts.wt. of lanthanum oxide. As a carrier molding method, a tablet molding method and an extrusion molding method can be employed and the carrier can by molded by molding stock materials themselves into a honeycomb or foam shape. The baking temp. of the carrier is pref. about 1,500W550°C.