Exhaust gas purification catalyst

Abstract

A catalytic matter comprises alumina particles. A compound oxide is loaded on surfaces of the alumina particles. The compound oxide contains cerium, zirconium, and lanthanum, but not aluminum. A catalytic metal is loaded on the surfaces of the alumina particles. The catalytic matter may be manufactured by preparing a first acidic solution containing aluminum, adding a first basic solution to the first acidic solution, thereby obtaining a second basic solution and precipitating a first hydroxide in the second basic solution, preparing a second acidic solution containing cerium, zirconium and lanthanum, adding the second acidic solution to the first hydroxide, thereby precipitating a second hydroxide on the first hydroxide, drying the first and second hydroxides to obtain an oxide matter, and loading a catalytic metal on the oxide matter. By loading the compound oxide containing cerium as an oxygen storage material on the alumina particle surfaces, the amount of the oxygen storage material on the surfaces of alumina particles may be increased, and the catalytic metal may loaded on or in the proximity of the oxygen storage material. Therefore, the catalytic metal may be supplied with sufficient amount of active oxygen to purify the exhaust gas.

Dependencies are inferred from the claim text.