Iridium Oxide Coordinatively Unsaturated Active Sites Govern the Electrocatalytic Oxidation of Water
Name
Advanced Energy Materials - 2024 - Velasco Vélez - Iridium Oxide Coordinatively Unsaturated Active Sites Govern the.pdf
Description
Published version
Size
2.32 MB
Format
Adobe PDF
Checksum (MD5)
ed41c68be749e2c769dc40b4824b2f88
Author(s)
Velasco Vélez, Juan Jesús
Bernsmeier, Denis
Mom, Rik V.
Zeller, Patrick
Shao‐Horn, Yang
Roldan Cuenya, Beatriz
Knop‐Gericke, Axel
Schlögl, Robert
Jones, Travis E.
Date Issued
March 11, 2024
Journal
Advanced Energy Materials
Publisher
Wiley
Citation
J. J. Velasco Vélez, D. Bernsmeier, R. V. Mom, P. Zeller, Y. Shao-Horn, B. Roldan Cuenya, A. Knop-Gericke, R. Schlögl, T. E. Jones, Iridium Oxide Coordinatively Unsaturated Active Sites Govern the Electrocatalytic Oxidation of Water. Adv. Energy Mater. 2024, 2303407.
Version
Final published version
Abstract
A special membrane electrode assembly to measure operando X‐ray absorption spectra and resonant photoemission spectra of mesoporous templated iridium oxide films is used. These films are calcined to different temperatures to mediate the catalyst activity. By combining operando resonant photoemission measurements of different films with ab initio simulations these are able to unambiguously distinguish µ2‐O (bridging oxygen) and µ1‐O (terminal oxygen) in the near‐surface regions of the catalysts. The intrinsic activity of iridium oxide scales with the formation of µ1‐O (terminal oxygen) is found. Importantly, it is shown that the peroxo species do not accumulate under reaction conditions. Rather, the formation of µ1‐O species, which are active in O−O bond formation during the OER, is the most oxidized oxygen species observed, which is consistent with an O−O rate‐limiting step. Thus, the oxygen species taking part in the electrochemical oxidation of water on iridium electrodes are more involved and complex than previously stated. This result highlights the importance of employing theory together with true and complementary operando measurements capable of probing different aspects of catalysts surfaces during operation.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1002/aenm.202303407
