The invention is a method for producing a metal oxide catalyst useful for purifying exhaust gases and waste gases from combustion processes.

This paper introduces some kinds of catalysts for automobile exhaust purification, such as Three Way Catalysts (TWCs), perovskite oxide catalyst, and molecular sieve catalyst by metal ions.

Rare earth perovskite-type oxide catalyst as a substitute for traditional rare metal catalyst has a great potential to purify automotive emission due to good catalytic activity and low cost.