Iridium Oxide Coordinatively Unsaturated Active Sites Govern the Electrocatalytic Oxidation of Water
A special membrane electrode assembly to measure <jats:italic>operando</jats:italic> 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 co...
| Main Authors: | , , , , , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
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Wiley
2024
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| Online Access: | https://hdl.handle.net/1721.1/154278 |
| _version_ | 1824458381901955072 |
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| author | 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. |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering 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. |
| author_sort | Velasco Vélez, Juan Jesús |
| collection | MIT |
| description | A special membrane electrode assembly to measure <jats:italic>operando</jats:italic> 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 <jats:italic>operando</jats:italic> resonant photoemission measurements of different films with ab initio simulations these are able to unambiguously distinguish µ<jats:sub>2</jats:sub>‐O (bridging oxygen) and µ<jats:sub>1</jats:sub>‐O (terminal oxygen) in the near‐surface regions of the catalysts. The intrinsic activity of iridium oxide scales with the formation of µ<jats:sub>1</jats:sub>‐O (terminal oxygen) is found. Importantly, it is shown that the peroxo species do not accumulate under reaction conditions. Rather, the formation of µ<jats:sub>1</jats:sub>‐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 <jats:italic>operando</jats:italic> measurements capable of probing different aspects of catalysts surfaces during operation. |
| first_indexed | 2024-09-23T15:47:03Z |
| format | Article |
| id | mit-1721.1/154278 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2025-02-19T04:25:00Z |
| publishDate | 2024 |
| publisher | Wiley |
| record_format | dspace |
| spelling | mit-1721.1/1542782025-01-06T04:17:03Z Iridium Oxide Coordinatively Unsaturated Active Sites Govern the Electrocatalytic Oxidation of Water 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. Massachusetts Institute of Technology. Department of Mechanical Engineering A special membrane electrode assembly to measure <jats:italic>operando</jats:italic> 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 <jats:italic>operando</jats:italic> resonant photoemission measurements of different films with ab initio simulations these are able to unambiguously distinguish µ<jats:sub>2</jats:sub>‐O (bridging oxygen) and µ<jats:sub>1</jats:sub>‐O (terminal oxygen) in the near‐surface regions of the catalysts. The intrinsic activity of iridium oxide scales with the formation of µ<jats:sub>1</jats:sub>‐O (terminal oxygen) is found. Importantly, it is shown that the peroxo species do not accumulate under reaction conditions. Rather, the formation of µ<jats:sub>1</jats:sub>‐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 <jats:italic>operando</jats:italic> measurements capable of probing different aspects of catalysts surfaces during operation. 2024-04-25T12:35:37Z 2024-04-25T12:35:37Z 2024-03-11 2024-04-24T21:21:16Z Article http://purl.org/eprint/type/JournalArticle 1614-6832 1614-6840 https://hdl.handle.net/1721.1/154278 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. en 10.1002/aenm.202303407 Advanced Energy Materials Creative Commons Attribution-NonCommercial-NoDerivs License https://creativecommons.org/licenses/by-nc-nd/4.0/ application/pdf Wiley Wiley |
| spellingShingle | 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. Iridium Oxide Coordinatively Unsaturated Active Sites Govern the Electrocatalytic Oxidation of Water |
| title | Iridium Oxide Coordinatively Unsaturated Active Sites Govern the Electrocatalytic Oxidation of Water |
| title_full | Iridium Oxide Coordinatively Unsaturated Active Sites Govern the Electrocatalytic Oxidation of Water |
| title_fullStr | Iridium Oxide Coordinatively Unsaturated Active Sites Govern the Electrocatalytic Oxidation of Water |
| title_full_unstemmed | Iridium Oxide Coordinatively Unsaturated Active Sites Govern the Electrocatalytic Oxidation of Water |
| title_short | Iridium Oxide Coordinatively Unsaturated Active Sites Govern the Electrocatalytic Oxidation of Water |
| title_sort | iridium oxide coordinatively unsaturated active sites govern the electrocatalytic oxidation of water |
| url | https://hdl.handle.net/1721.1/154278 |
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