What is a catalyst
In a chemical reaction, substances that can change the chemical reaction rate of the reactants (increase or decrease) without changing the chemical equilibrium, and their mass and chemical properties do not change before and after the chemical reaction are called catalysts (solid catalysts are also called catalysts).
What is the catalyst for
The catalyst can change the chemical reaction rate of other substances, and the "change" here includes speeding up and slowing down, that is, the catalyst can speed up the reaction rate or slow down the reaction rate.
Type of catalyst
1, heterogeneous catalysis: catalysis that occurs at the two-phase interface, usually used in the range when the catalyst is a porous solid and the reactant is a liquid or gas. In the heterogeneous catalytic reaction, the solid catalyst chemical adsorption of the reactant molecules, these are visible to the naked eye, so that the reactant molecules are activated, can change the performance, the surface of the solid catalyst is not uniform this point must be known, only part of the point chemical adsorption of the reactant molecules.
2, biocatalysis: the components also include the catalytic reaction carried out under the action of enzymes in the organism. The catalysis of enzyme has the characteristics of high selectivity, high catalytic activity, which can make the catalytic speed become faster, and the reaction conditions are mild, which can not be ignored, but it is greatly affected by temperature, pH value in solution, ionic strength and other factors.
3, automatic catalysis: the self-catalysis of the reaction product, for the production will have a great role, in some reactions, some reaction products or intermediates have catalytic function, so that the reaction after a period of induction rate greatly accelerated, so as to reduce the time cost, autocatalysis is one of the necessary conditions for chemical oscillation.
The main application areas of catalysts
Catalysts play an important role in chemical production, and most chemical production involves catalysts. For example, in the petroleum refining process, the use of high-efficiency catalysts to produce gasoline, kerosene, etc.; In automobile exhaust treatment, the catalyst is used to promote the conversion of harmful gases; Both the brewing and pharmaceutical industries use enzymes as catalysts, and some enzyme preparations are valuable medicines.