(chemistry) The increase of the rate of a chemical reaction, induced by a catalyst.

(chemistry) Catalysis in which the catalyst is present in a separate phase; normally the catalyst is a solid and the reactants are gas or liquid; it proceeds by the reaction of chemisorbed complexes.

(chemistry) Catalysis in which the catalyst is present in the same phase as the reactants; normally dissolved in the same solvent.

(chemistry) A process in which the rate of a reaction in a heterogeneous two-phase system is enhanced by the addition of a substance that transfers one of the reactants across the interface between the two phases.