in catalysis
A relatively small quantity of one or more substances, which when added to a @C00876@ improves the activity, the @S05563@, or the useful @L03515@ of the @C00876@. In general, a promoter may either augment a desired reaction or suppress an undesired one.
PAC, 1976, 46, 71. (Manual of Symbols and Terminology for Physicochemical Quantities and Units - Appendix II. Definitions, Terminology and Symbols in Colloid and Surface Chemistry. Part II: Heterogeneous Catalysis) on page 79 [Terms] [Paper]