Electrochemically Driven Water Oxidation by a Highly Active Ruthenium-Based CatalystShow others and affiliations
Number of Authors: 112019 (English)In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 12, no 10, p. 2251-2262Article in journal (Refereed) Published
Abstract [en]
The highly active ruthenium-based water oxidation catalyst [Ru-X(mcbp)(OHn)(py)(2)] [mcbp(2-)=2,6-bis(1-methyl-4-(carboxylate)benzimidazol-2-yl)pyridine; n=2, 1, and 0 for X=II, III, and IV, respectively], can be generated in a mixture of Ru-III and Ru-IV states from either [Ru-II(mcbp)(py)(2)] or [Ru-III(Hmcbp)(py)(2)](2+) precursors. The precursor complexes are isolated and characterized by single-crystal X-ray analysis, NMR, UV/Vis, EPR, and FTIR spectroscopy, ESI-HRMS, and elemental analysis, and their redox properties are studied in detail by electrochemical and spectroscopic methods. Unlike the parent catalyst [Ru(tda) (py)(2)] (tda(2-)=[2,2:6,2-terpyridine]-6,6-dicarboxylate), for which full transformation into the catalytically active species [Ru-IV(tda)(O)(py)(2)] could not be carried out, stoichiometric generation of the catalytically active Ru-aqua complex [Ru-X(mcbp)(OHn)(py)(2)] from the Ru-II precursor was achieved under mild conditions (pH7.0) and short reaction times. The redox properties of the catalyst were studied and its activity for electrocatalytic water oxidation was evaluated, reaching a maximum turnover frequency (TOFmax) of around 40000s(-1) at pH9.0 (from foot-of-the-wave analysis), which is comparable to the activity of the state-of-the-art catalyst [Ru-IV(tda)(O)(py)(2)].
Place, publisher, year, edition, pages
2019. Vol. 12, no 10, p. 2251-2262
Keywords [en]
artificial photosynthesis, electrocatalysis, homogeneous catalysis, ruthenium, water oxidation, Green & Sustainable Science & Technology
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:su:diva-171162DOI: 10.1002/cssc.201900097ISI: 000472806800021PubMedID: 30759324OAI: oai:DiVA.org:su-171162DiVA, id: diva2:1350456
2019-09-112019-09-112022-02-26Bibliographically approved