Catalysts/Additives
A catalyst is a substance that can alter the rate of a chemical reaction while maintaining its composition and mass unchanged before and after the reaction. A promoter (or auxiliary catalyst) is an auxiliary substance added to the catalytic system, which can improve the performance of the catalyst (such as activity, selectivity, and stability).
Their relationship can be summarized in one sentence: The catalyst is the "leading actor" in a chemical reaction, responsible for initiating and accelerating the key reactions; the additive is the "supporting role", although it does not directly play the leading role, it can make the "performance" of the leading actor more outstanding and stable.
