The catalyst can change the reaction rate in the chemical reaction, and the composition and the quality of the catalyst can be kept constant after the reaction. The catalyst that accelerates the reaction is called the positive catalyst, slows down called Negative Catalyst or slow agent. It said catalyst is a positive catalyst for the general correction. This kind of catalyst in the industry, especially the organic chemical industry used more, and has great significance, Such as sulfuric acid prepared by contacting, ammonia, hydrolysis of the ester and polysaccharide, Oil Hydrogenation, etc. Commonly used catalysts are mainly metal, metal oxide and inorganic acid. If the catalyst is solid, the substance of the reaction is gas, to form a multi-phase catalytic