Rare earth elements are widely used in many chemical reactions besides manufacturing petroleum cracking catalysts, such as rare earth oxides LaO3, Nd2O3, and Sm2O3 for cyclohexane dehydrogenation to benzene, and LnCoO3 replacing platinum for catalytic oxidation of ammonia to nitric acid. And used as a catalyst in the production of synthetic isoprene rubber and butadiene rubber. Automobile exhaust needs to oxidize CH and CO and reduce NOX to solve the current urban air pollution problem. Rare earth elements are the main raw materials for automotive exhaust purification catalysts. Rare earth catalysis is also used in many fields such as paint drying, plastic stabilizers, and rare earth polymer materials.