Catalysis
Catalysis, or Catalytic Action, a chemical process in which the reaction between two or more substances is influenced by the presence of a third substance called a catalyst. The catalyst, although it affects the reaction, remains unchanged when the reaction is completed.
Catalysts initiate, speed up, or slow down chemical reactions. (Those that slow down reactions are called negative catalysts.) They are involved in chemical reactions that occur in nature as well as those used in industrial processes or experimental work. The most important catalysts are enzymes, which are produced by all living things.
A promoter is a substance that has little catalytic ability of its own but increases the catalytic properties of a catalyst.