Electron deficient oxygen species in highly OER active iridium anodes characterized by X-ray absorption and emission spectroscopy
Water splitting is a promising technology for storing energy, yet it is challenged by the lack of stable anode materials that can overcome the sluggishness of the oxygen evolution reaction (OER). Iridium oxides are among the most active and stable OER catalysts, however how these materials achieve their performance remains under discussion. The activity of iridium based materials has been attributed to both high metal oxidation states and the appearance of O 2p holes. Herein we employ a combination of techniques-X-ray absorption at the Ir L<sub>II,III</sub>-edge, X-ray absorption and emission at the O K-edge, along with <i>ab initio</i> methods-to identify and characterize ligand holes present in highly OER-active X-ray amorphous oxides. We find, in agreement with the original proposition based on X-ray absorption measurement at the O K-edge, that O 2p holes are present in these materials and can be associated with the increased activity during OER.
Authors
- Lorena Alzate-Vargas (ORCID: https://orcid.org/0000-0002-4223-4046)
- Cheng‐Hao Chuang (ORCID: https://orcid.org/0000-0001-8161-1521)
- Lorenz J. Falling (ORCID: https://orcid.org/0000-0002-2622-5166)
- J. W. Chiou (ORCID: https://orcid.org/0000-0002-1801-7420)
- Bettina Valeska Lotsch (ORCID: https://orcid.org/0000-0002-3094-303X)
- Travis E. Jones (ORCID: https://orcid.org/0000-0001-8921-7641)
- Ting‐Shan Chan (ORCID: https://orcid.org/0000-0001-5220-1611)
- Sourav Laha (ORCID: https://orcid.org/0000-0002-4554-5042)
- W. F. Pong
Institutions
- Tamkang University (TW)
- Los Alamos National Laboratory (US)
- National Institute of Technology Durgapur (IN)
- National University of Kaohsiung (TW)
- ALBA Synchrotron (Spain) (ES)
- Max Planck Institute for Solid State Research (DE)
- National Synchrotron Radiation Research Center (TW)
- Los Alamos National Security (United States) (US)
- Technical University of Munich (DE)
Publication Details
- Journal
- Physical Chemistry Chemical Physics
- Published
- 2025-01-01
- DOI
- https://doi.org/10.1039/d4cp03415e
- Citations
- 2
- Primary Topic
- Semiconductor materials and devices
- Type
- article
- Field-Weighted Citation Impact
- 1.46
Funders
- Alexander von Humboldt-Stiftung
- Los Alamos National Laboratory