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Koncepce dynamického aktivního centra v heterogenní fotokatalytické oxidační reakci.
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SYSNO ASEP 0505588 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Koncepce dynamického aktivního centra v heterogenní fotokatalytické oxidační reakci. Title The Concept of a Dynamic Active Site in a Heterogeneous Photocatalytic Oxidation Reaction. Author(s) Klusoň, Petr (UCHP-M) RID, ORCID, SAI
Krýsa, J. (CZ)
Stavárek, Petr (UCHP-M) RID, ORCID, SAI
Hejda, Stanislav (UCHP-M) RID, ORCID, SAI
Vychodilová, Hana (UCHP-M) RID, SAI
Dzik, P. (CZ)
Veselý, M. (CZ)
Krystyník, Pavel (UCHP-M) RID, SAI, ORCIDSource Title Chemické listy. - : Česká společnost chemická - ISSN 0009-2770
Roč. 113, č. 6 (2019), s. 391-396Number of pages 6 s. Language cze - Czech Country CZ - Czech Republic Keywords active centre ; reaction rate ; photon Subject RIV CI - Industrial Chemistry, Chemical Engineering OECD category Chemical process engineering R&D Projects VI20162019037 GA MV - Ministry of Interior (MV) Method of publishing Limited access Institutional support UCHP-M - RVO:67985858 UT WOS 000473231800007 EID SCOPUS 85069471784 Annotation Zavedení koncepce dynamického aktivního centra (DAS) v heterogenní fotokatalytické oxidaci umožňuje pro materiály, u nichž byl tento typ reakčního místa identifikován, využít standardní kinetické algoritmy a rovnice používané v heterogenní katalýze. Použití DAS je však z praktických důvodů spíše omezeno na částicové tenké vrstvy, u kterých lze bez větších experimentálních potíží provést světlem indukovaný elektrochemický experiment. Jeho cílem je především vyhodnotit kvalitativní charakter odezvy světlocitlivé vrstvy na přítomnost fotonů. Kvantitativní popis je rovněž důležitý, ovšem pro objektivizaci existence DAS není klíčový. Description in English In this communication we wished to introduce the concept of a dynamic active site (CDAS) for oxidation of thin films photocatalysts as a certain analogy to the common conceptions of active sites in heterogeneous catalysts. The main intention was to show an experimental algorithm which should be applied if two (or more) different thin film photocatalysts are to be compared in a particular reaction. It is unfortunately very common that the performances of two particular photocatalysts are compared and conclusions are drawn, but such a comparison is incorrect from principle reasons. It was shown here that the existence of a dynamic active site must be validated first for both (or more) catalytic species being compared, and only if it is successful at this stage. standard kinetic data treatment and their comparisons are possible. Polarization curves provided by the linear voltammetry (I-E/current-voltage) reflect the ability of the light sensitive semicon-ducting films to generate the carriers (electrons and holes) upon illumination. The stability of the generated photocurrent level (the plateau) indicates the same rate of the formation of charges and their recombination. If this is true, the electrochemical system occurs in the state of dynamic equilibrium. Under model conditions, it is thus possible to assess whether or not a particular photocatalytic material tends to generate h+ species in the same rate as it vanishes. If the answer is positive, the holes h+ might be formally referred to as standard active sites since upon fixed illumination their abundance is constant in time. Workplace Institute of Chemical Process Fundamentals Contact Eva Jirsová, jirsova@icpf.cas.cz, Tel.: 220 390 227 Year of Publishing 2020 Electronic address http://hdl.handle.net/11104/0298432
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