The electronic structure of iridium oxide electrodes active in water splitting

DOI: 10.1039/C5CP06997A
PMID: 26700139

Authors: V. Pfeifer (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , T. E. Jones (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , J. J. Velasco Vélez (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , C. Massué (Fritz-Haber-Institut der Max-Planck-Gesellschaft; Max-Planck-Institut für Chemische Energiekonversion) , M. T. Greiner (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , R. Arrigo (Diamond Light Source) , D. Teschner (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , F. Girgsdies (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , M. Scherzer (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , J. Allan (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , M. Hashagen (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , G. Weinberg (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , S. Piccinin (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , M. Hävecker (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , A. Knop-Gericke (Fritz-Haber-Institut der Max-Planck-Gesellschaft) , R. Schlögl (Fritz-Haber-Institut der Max-Planck-Gesellschaft)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Chemistry Chemical Physics , VOL 18 , PAGES 2292 - 2296

State: Published (Approved)
Published: December 2015

Abstract: Iridium oxide based electrodes are among the most promising candidates for electrocatalyzing the oxygen evolution reaction, making it imperative to understand their chemical/electronic structure. However, the complexity of iridium oxide's electronic structure makes it particularly difficult to experimentally determine the chemical state of the active surface species. To achieve an accurate understanding of the electronic structure of iridium oxide surfaces, we have combined synchrotron-based X-ray photoemission and absorption spectroscopies with ab initio calculations. Our investigation reveals a pre-edge feature in the O K-edge of highly catalytically active X-ray amorphous iridium oxides that we have identified as O 2p hole states forming in conjunction with IrIII. These electronic defects in the near-surface region of the anionic and cationic framework are likely critical for the enhanced activity of amorphous iridium oxides relative to their crystalline counterparts.

Diamond Keywords: Hydrogen Storage

Subject Areas: Physics, Chemistry, Energy

Facility: BESSYII

Added On: 25/01/2016 16:45

Documents:
c5cp06997a.pdf

Discipline Tags:

Energy Storage Energy Physics Physical Chemistry Hard condensed matter - structures Catalysis Energy Materials Chemistry Materials Science

Technical Tags: