New aspect of the mechanism of photocatalytic oxidation of organic compounds by polyoxometalates in aqueous solutions. The selective photooxidation of propan-2-ol to propanone: The role of OH radicals

Mylonas, A; Hiskia, A; Androulaki, E; Dimotikali, D; Papaconstantinou, E

dc.contributor.author	Mylonas, A	en
dc.contributor.author	Hiskia, A	en
dc.contributor.author	Androulaki, E	en
dc.contributor.author	Dimotikali, D	en
dc.contributor.author	Papaconstantinou, E	en
dc.date.accessioned	2014-03-01T01:48:40Z
dc.date.available	2014-03-01T01:48:40Z
dc.date.issued	1999	en
dc.identifier.issn	14639076	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/25545
dc.subject.other	2 propanol	en
dc.subject.other	acetone	en
dc.subject.other	carbon dioxide	en
dc.subject.other	hydroxyl radical	en
dc.subject.other	metal oxide	en
dc.subject.other	organic compound	en
dc.subject.other	oxygen	en
dc.subject.other	water	en
dc.subject.other	aqueous solution	en
dc.subject.other	article	en
dc.subject.other	catalysis	en
dc.subject.other	chemical reaction	en
dc.subject.other	photochemistry	en
dc.subject.other	photooxidation	en
dc.subject.other	thermodynamics	en
dc.title	New aspect of the mechanism of photocatalytic oxidation of organic compounds by polyoxometalates in aqueous solutions. The selective photooxidation of propan-2-ol to propanone: The role of OH radicals	en
heal.type	journalArticle	en
heal.identifier.primary	10.1039/a808104b	en
heal.identifier.secondary	http://dx.doi.org/10.1039/a808104b	en
heal.publicationDate	1999	en
heal.abstract	The excited state of polyoxometalates, (POM) arising from absorption of light at the O → M charge transfer (CT) band (near-VIS and UV light), is a powerful oxidizing reagent. The oxidizing ability is manifested, mainly, through formation of OH radicals arising from the reaction of the excited POM with adsorbed water. The currently accepted mechanism of H-abstraction as the initial reaction of excited POM with organic substrates (mainly alcohols) is modified by addition of one more step that involves the formation of OH radicals which, as is well known, react with organic substrates, mainly alcohols, by H-abstraction. In view of the formation of OH radicals, and the high oxidizing ability of the excited POM, the photochemical selective oxidation of organic substrates, reported so far, in aqueous solutions, should be considered with reservation. Propan-2-ol is, indeed, selectively oxidized to propanone in the presence of PW12O403-. The selectivity is, however, a kinetic phenomenon rather than a thermodynamic one. Both photoreactions, as is the case with numerous other organic compounds, give, as final products, CO2 and H2O.	en
heal.journalName	Physical Chemistry Chemical Physics	en
dc.identifier.doi	10.1039/a808104b	en
dc.identifier.volume	1	en
dc.identifier.issue	3	en
dc.identifier.spage	437	en
dc.identifier.epage	440	en