A relatively small quantity of one or more substances, which when added to a
catalyst improves the activity, the
selectivity,
or the useful lifetime of the
catalyst. In general, a promoter may either augment a desired reaction or suppress an undesired one.
Source:
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
