Most of the hydrogenation reactions are exothermic, and most of them are carried out at high temperatures. The hydrogen and most of the materials used have the danger of ignition and explosion, and some of the materials, products or intermediate products are toxic and corrosive. In case of leakage, reactor blockage and other failures, there is a great risk of fire and explosion. 

The first catalyst production plant in China was the catalyst department of Yongli Asia Plant, which was renamed as Nanjing Chemical Industry Company Catalyst Plant in 1959. In 1950, it started to produce AI type ammonia catalysts, C-2 type carbon monoxide high temperature conversion catalysts and VI type vanadium catalysts for sulfur dioxide oxidation, and then gradually completed the production of various catalysts for ammonia industry. By 1984, more than 40 units had produced catalysts for sulfuric acid, nitric acid and ammonia industries.