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Catalysis
Catalysis (/kəˈtæləsɪs/) is the increase in rate of a chemical reaction due to an added substance known as a catalyst[1][2] (/ˈkætəlɪst/). Catalysts are not consumed by the reaction and remain unchanged after it.[3] If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice;[4] mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst.
The rate increase occurs because the catalyst allows the reaction to occur by an alternative mechanism which may be much faster than the non-catalyzed mechanism. However the non-catalyzed mechanism does remain possible, so that the total rate (catalyzed plus non-catalyzed) can only increase in the presence of the catalyst and never decrease.[5]
Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usually gaseous or liquid) as the reactant, or heterogeneous, whose components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category.
Catalysis is ubiquitous in chemical industry of all kinds.[6] Estimates are that 90% of all commercially produced chemical products involve catalysts at some stage in the process of their manufacture.
The term "catalyst" is derived from Greek καταλύειν, kataluein, meaning "loosen" or "untie". The concept of catalysis was invented by chemist Elizabeth Fulhame, based on her novel work in oxidation-reduction experiments.[7][8]
- ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "catalyst". doi:10.1351/goldbook.C00876
- ^ Masel, Richard I (2001). Chemical Kinetics and Catalysis. New York: Wiley-Interscience. ISBN 0-471-24197-0.
- ^ Steinfeld, Jeffrey I.; Francisco, Joseph S.; Hase, William L. (1999). Chemical Kinetics and Dynamics (2nd ed.). Prentice Hall. p. 147. ISBN 0-13-737123-3.
A catalyst is defined as a chemical substance which increases the rate of a chemical reaction without itself being consumed in the reaction.
- ^ Lerner, Louise (2011). "7 things you may not know about catalysis". Argonne National Laboratory.
- ^ Laidler, Keith J.; Meiser, John H. (1982). Physical Chemistry. Benjamin/Cummings. p. 425. ISBN 0-8053-5682-7.
Inhibitors do not work by introducing a higher reaction path; this would not reduce the rate, since the reaction would continue to occur by the alternative mechanism
- ^ Carroll, Gregory T.; Kirschman, David L. (January 23, 2023). "Catalytic Surgical Smoke Filtration Unit Reduces Formaldehyde Levels in a Simulated Operating Room Environment". ACS Chemical Health & Safety. 30 (1): 21–28. doi:10.1021/acs.chas.2c00071. ISSN 1871-5532. S2CID 255047115.
- ^ Laidler, Keith J.; Cornish-Bowden, Athel (1997). ""Elizabeth Fulhame and the discovery of catalysis: 100 years before Buchner" (PDF). In Cornish-Bowden, Athel (ed.). New beer in an old bottle : Eduard Buchner and the growth of biochemical knowledge. Valencia: Universitat de Valencia. pp. 123–126. ISBN 9788437033280. Archived from the original (PDF) on January 23, 2015. Retrieved March 14, 2021.
- ^ Rayner-Canham, Marelene; Rayner-Canham, Geoffrey William (2001). Women in Chemistry: Their Changing Roles from Alchemical Times to the Mid-Twentieth Century. American Chemical Society. ISBN 978-0-8412-3522-9.
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