Metal-hydroxyls mediate intramolecular proton transfer in heterogeneous O–O bond formation
Metal (hydro)oxides are among the most effective heterogeneous water oxidation catalysts. Elucidating the interactions between oxygen-bridged metal sites at a molecular level is essential for developing high-performing electrocatalysts. Here we demonstrate that adjacent metal-hydroxyl groups function as intramolecular proton-electron transfer relays to enhance water oxidation kinetics. We achieved this using a well-defined molecular platform with an aza-fused π-conjugated microporous polymer that coordinates molecular Ni or Ni-Fe sites that emulate the structure of the most active edge sites in Ni-Fe materials for studying the heterogeneous water oxidation mechanism. We combine experimental and computational results to reveal the origin of pH-dependent reaction kinetics for O-O bond formation. We find both the anions in solution and the adjacent Ni<sup>3+</sup>-OH site act as proton transfer relays, facilitating O-O bond formation and leading to pH-dependent water oxidation kinetics. This study provides significant insights into the critical role of electrolyte pH in water oxidation electrocatalysis and enhancement of water oxidation activity in Ni-Fe systems.
Authors
- Mårten S. G. Ahlquist (ORCID: https://orcid.org/0000-0002-1553-4027)
- Licheng Sun (ORCID: https://orcid.org/0000-0002-4521-2870)
- Marc T. M. Koper (ORCID: https://orcid.org/0000-0001-6777-4594)
- Rile Ge
- Shaoqi Zhan (ORCID: https://orcid.org/0000-0002-6383-1771)
- Linqin Wang (ORCID: https://orcid.org/0000-0001-6293-6742)
- Sumbal Farid
- Wenlong Li (ORCID: https://orcid.org/0009-0002-2812-7057)
- Tianqi Liu (ORCID: https://orcid.org/0000-0002-0672-9965)
- Yawen Liu (ORCID: https://orcid.org/0000-0002-9500-7373)
- Fusheng Li (ORCID: https://orcid.org/0000-0003-3455-0855)
- Junhu Wang (ORCID: https://orcid.org/0000-0003-1987-2522)
- Hao Yang (ORCID: https://orcid.org/0000-0002-1303-0482)
Institutions
- Sinopec (China) (CN)
- Leiden University (NL)
- Uppsala University (SE)
- Dalian Institute of Chemical Physics (CN)
- Dalian University of Technology (CN)
- Westlake University (CN)
- Dalian University (CN)
- KTH Royal Institute of Technology (SE)
Publication Details
- Journal
- Nature Chemistry
- Published
- 2025-11-14
- DOI
- https://doi.org/10.1038/s41557-025-01993-8
- Citations
- 7
- Primary Topic
- Electrocatalysts for Energy Conversion
- Type
- article
- Field-Weighted Citation Impact
- 2.54
Funders
- Westlake University
- National Natural Science Foundation of China
- Kungliga Tekniska Högskolan
- Stockholms Universitet
- Deutsches Elektronen-Synchrotron
- Fundamental Research Funds for the Central Universities
- National Supercomputing Center, Korea Institute of Science and Technology Information