A cycle of chemical reactions, involving several chemical compounds, that depends on the presence of a specific compound which remains unchanged during these reactions.
A catalytic cycle in chemistry is a concept that appreciates the notion that in a chemical reaction a catalyst is often first consumed and then regenerated in the course of a catalytic reaction sequence thereby elaborating on the classical view that of a catalyst not taking part in the reaction itself. Catalytic cycles are commonplace in biochemistry and organometallic chemistry for example in the Monsanto process, the Wacker process and the Heck reaction.