Catalyzed reactions are typically used to accelerate the rate by which a specific chemistry proceeds. Essentially, the action of the catalyst is to provide an alternative, lower energy pathway for the reaction. For this to occur, the catalytic substance interacts with a reactant and forms an intermediate compound. This intermediate is transient in that after it forms, it breaks apart leaving the original catalyst species unchanged. A catalyst is not affected by the reaction as far as the chemical structure or mass at reaction completion.
There are two general types of catalyzed reactions:
- Heterogeneous Catalyzed Reaction is when the catalyst and the reactant exist in two different phases, such as a solid catalyst with a reactant in solution.
- Homogeneous Catalyzed Reaction is when the catalyst and the reactant are in the same phase, such as when the catalyst and the reactants are dissolved in the same solution.