catalyst

https://doi.org/10.1351/goldbook.C00876
A substance that increases the rate of a reaction without modifying the overall standard Gibbs energy change in the reaction; the process is called @C00874-1@. The catalyst is both a @R05163@ and @P04861@ of the reaction. The words catalyst and @C00874-1@ should not be used when the added substance reduces the @R05156@ (see @I03035@). @C00874-2@ can be classified as @H02846@, in which only one phase is involved, and @H02804@, in which the reaction occurs at or near an @I03082@ between phases. @C00874-2@ brought about by one of the products of a reaction is called autocatalysis. @C00874-2@ brought about by a group on a reactant molecule itself is called @I03131@. The term @C00874-1@ is also often used when the substance is consumed in the reaction (for example: base-catalysed @H02902@ of @E02219@). Strictly, such a substance should be called an @A00104@.
See also:
autocatalytic reaction
,
bifunctional catalysis
,
catalytic coefficient
,
electron-transfer catalysis
,
general acid catalysis
,
general base catalysis
,
intramolecular catalysis
,
micellar catalysis
,
Michaelis–Menten kinetics
,
phase-transfer catalysis
,
pseudo-catalysis
,
rate of reaction
,
specific catalysis
Source:
PAC, 1996, 68, 149. (A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)) [Terms] [Paper]
See also:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) [Terms] [Paper]
PAC, 1993, 65, 2291. (Nomenclature of kinetic methods of analysis (IUPAC Recommendations 1993)) [Terms] [Paper]
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) [Terms] [Paper]
Cite as: IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). Online version (2019-) created by S. J. Chalk. ISBN 0-9678550-9-8. https://doi.org/10.1351/goldbook.
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