{"term":{"id":"13997","title":"Brunauer–Emmett–Teller surface area","longtitle":"IUPAC Gold Book - Brunauer–Emmett–Teller surface area","doi":"10.1351\/goldbook.13997","code":"13997","status":"current","initialism":"<em>initialism<\/em>: BET","definitions":[{"id":1,"text":"Specific surface area (\\(\\pu{m2 kg-1}\\)) determined from the adsorption isotherm of a gas with the help of the Brunauer, Emmett, and Teller model using the conventional value for the molecular cross-section.","notes":{"1":"The most common gas used is \\(\\ce{N2}\\) with the conventional molecular cross-section of \\(\\pu{0.162 nm2}\\). With nitrogen, the total area is measured; this area includes the area in pores (that may not be reached by light). In this case, the expression \\(\\rm{BET}(\\ce{N2})\\) is used.","2":"The area-related parameters do not characterise the catalyst in photocatalysis as they do in heterogeneous dark catalysis. The properties of a photocatalyst are not directly proportional to their area, in view of the fact that light does not equally reach every part of the surface area or particle."},"links":[{"term":"area-related parameters","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/13992"}],"sources":["PAC, 2011, 83, 931. 'Glossary of terms used in photocatalysis and radiation catalysis (IUPAC Recommendations 2011)' on page 943 (https:\/\/doi.org\/10.1351\/PAC-REC-09-09-36)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/13997\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/13997\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/13997\/plain"},"citation":"Citation: 'Brunauer–Emmett–Teller surface area' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351\/goldbook.13997","license":"The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/) for individual terms.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.","accessed":"2026-06-20T09:05:29+00:00"}}