Surface Electron-Hole Rich Species Active in the Electrocatalytic Water Oxidation.

Autor: Velasco-Vélez JJ; Department of Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470, Germany.; Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin 14195, Germany., Carbonio EA; Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin 14195, Germany.; Helmholtz-Center Berlin for Materials and Energy, BESSY II, Berlin 12489, Germany., Chuang CH; Department of Physics, Tamkang University, New Taipei City 25137, Taiwan., Hsu CJ; Department of Physics, Tamkang University, New Taipei City 25137, Taiwan., Lee JF; National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan., Arrigo R; School of Sciences, University of Salford, Environment and Life, Cockcroft building, M5 4WT, Manchester, U.K., Hävecker M; Department of Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470, Germany.; Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin 14195, Germany., Wang R; Department of Engineering, University of Cambridge, Cambridge CB3 0FA, U.K., Plodinec M; Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin 14195, Germany.; Rudjer Boskovic Institute, Bijenicka 54, HR-10000 Zagreb, Croatia., Wang FR; Department of Chemical Engineering, University College London, Torrington Placa, London WC1E7JE, U.K., Centeno A; Graphenea, San Sebastian 20018, Spain., Zurutuza A; Graphenea, San Sebastian 20018, Spain., Falling LJ; Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin 14195, Germany., Mom RV; Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin 14195, Germany., Hofmann S; Department of Engineering, University of Cambridge, Cambridge CB3 0FA, U.K., Schlögl R; Department of Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470, Germany.; Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin 14195, Germany., Knop-Gericke A; Department of Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470, Germany.; Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin 14195, Germany., Jones TE; Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin 14195, Germany.
Jazyk: angličtina
Zdroj: Journal of the American Chemical Society [J Am Chem Soc] 2021 Aug 18; Vol. 143 (32), pp. 12524-12534. Date of Electronic Publication: 2021 Aug 06.
DOI: 10.1021/jacs.1c01655
Abstrakt: Iridium and ruthenium and their oxides/hydroxides are the best candidates for the oxygen evolution reaction under harsh acidic conditions owing to the low overpotentials observed for Ru- and Ir-based anodes and the high corrosion resistance of Ir-oxides. Herein, by means of cutting edge operando surface and bulk sensitive X-ray spectroscopy techniques, specifically designed electrode nanofabrication and ab initio DFT calculations, we were able to reveal the electronic structure of the active IrO x centers (i.e., oxidation state) during electrocatalytic oxidation of water in the surface and bulk of high-performance Ir-based catalysts. We found the oxygen evolution reaction is controlled by the formation of empty Ir 5d states in the surface ascribed to the formation of formally Ir V species leading to the appearance of electron-deficient oxygen species bound to single iridium atoms (μ 1 -O and μ 1 -OH) that are responsible for water activation and oxidation. Oxygen bound to three iridium centers (μ 3 -O) remains the dominant species in the bulk but do not participate directly in the electrocatalytic reaction, suggesting bulk oxidation is limited. In addition a high coverage of a μ 1 -OO (peroxo) species during the OER is excluded. Moreover, we provide the first photoelectron spectroscopic evidence in bulk electrolyte that the higher surface-to-bulk ratio in thinner electrodes enhances the material usage involving the precipitation of a significant part of the electrode surface and near-surface active species.
Databáze: MEDLINE
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