Microsecond X‐ray Absorption Spectroscopy Identification of CoI Intermediates in Cobaloxime‐Catalyzed Hydrogen Evolution. Issue 43 (4th September 2015)

• Record Type: Journal Article
• Authors: Smolentsev, Grigory; Cecconi, Bianca; Guda, Alexander; Chavarot‐Kerlidou, Murielle; van Bokhoven, Jeroen A.; Nachtegaal, Maarten; Artero, Vincent
• Is Part Of: Chemistry. Volume 21:Issue 43(2015)
• Page Start: 15158
• Page End: 15162
• Publication Date: 2015-09-04
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201502900
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Rational development of efficient photocatalytic systems for hydrogen production requires understanding the catalytic mechanism and detailed information about the structure of intermediates in the catalytic cycle. We demonstrate how time‐resolved X‐ray absorption spectroscopy in the microsecond time range can be used to identify such intermediates and to determine their local geometric structure. This method was used to obtain the solution structure of the Co^I intermediate of cobaloxime, which is a non‐noble metal catalyst for solar hydrogen production from water. Distances between cobalt and the nearest ligands including two solvent molecules and displacement of the cobalt atom out of plane formed by the planar ligands have been determined. Combining in situ X‐ray absorption and UV/Vis data, we demonstrate how slight modification of the catalyst structure can lead to the formation of a catalytically inactive Co^I state under similar conditions. Possible deactivation mechanisms are discussed.</p> </abstract>