Catalytic

Catalytic describes anything related to catalysis, the acceleration of a chemical reaction by a substance called a catalyst. In a catalytic process, the catalyst provides an alternative reaction pathway with a lower activation energy, allowing reactants to convert to products more rapidly than in the uncatalyzed process. Catalysts are not consumed by the overall reaction; they are regenerated at the end of the catalytic cycle and can enable many turnover events.

Catalysis can be categorized by the phase of the catalyst. Heterogeneous catalysis uses a solid catalyst with reactants in liquid or gas form, often involving surface processes and adsorption. Homogeneous catalysis features catalysts and reactants in the same phase, typically liquids, and frequently relies on well-defined molecular mechanisms. Enzymatic catalysis is a major branch of biocatalysis, where biological macromolecules—enzymes—achieve highly specific transformations under mild conditions. Catalytic activity may involve adsorption, formation of reaction intermediates, and regeneration of the active site; some reactions proceed via autocatalysis, where a product acts as a catalyst for its own formation.

Applications span industry and the environment. Industrially important catalysts enable processes such as catalytic cracking in petroleum refining, ammonia synthesis via the Haber-Bosch process, and methanol production. Automotive catalytic converters employ noble metals like platinum, palladium, and rhodium to convert pollutants (carbon monoxide, nitrogen oxides, and hydrocarbons) into less harmful substances. In research and synthesis, catalysts are used to achieve enantioselective or highly selective transformations, expanding the range of feasible chemical products.

The word catalytic derives from the concept of catalysis, from Greek roots meaning to loosen or dissolve, indicating how a catalyst alters a reaction pathway rather than being consumed.