catalysis (rus. катализ) — acceleration of a chemical reaction owing to the presence of substances (catalysts) that enter into the intermediate chemical interactions with the reagents or intermediates, yet regain their original chemical composition after each cycle of such interactions.

Description

A general theory of catalysis does not exist, but a number of general laws of catalysis have been identified. The fundamental generalisations based on the material of practical catalysis include the following assertions: 1) a catalyst does not shift the chemical equilibrium, i.e. it equally accelerates both direct and reverse reactions, 2) intermediates are formed between the reagents and the catalyst, and 3) the presence of a catalyst decreases the activation energy of the reaction.

By mechanism all catalytic processes are divided on the redox catalysis (oxidation, reduction, hydrogenation, dehydrogenation, etc.), acid-base catalysis (cracking, hydration, dehydration, isomerisation and condensation of organic substances, etc.), and catalysis by metal complexes (polymerisation of olefins, hydroformylation, etc.).

Authors

  • Andrey V. Smirnov
  • Nikolay N. Tolkachev

Sources

  1. G.K. Boreskov. Heterogeneous catalysis. — Nova Publishers, 2003. 236 p.
  2. M.D. Navalikhina, O.V. Krylov. Heterogeneous hydrogenation catalysts — RUSS CHEM REV, 1998.