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Dissolved Fe species enable a cooperative solid–molecular mechanism for the oxygen evolution reaction on NiFe-based catalysts

Nature Catalysis volume 8, pages 523–535 (2025)Cite this article

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Abstract

The oxygen evolution reaction is a key process in many energy technologies, but improving its efficiency remains challenging due to the energy scaling relationships that limit the reaction kinetics on conventional single-active-site solid catalysts. Here we report a cooperative solid–molecular mechanism for oxygen evolution on NiFe-based hydroxide electrocatalysts. By identifying the critical interfacial species and understanding their dynamics, we find that molecular FeO42− species, derived from the dissolution of Fe from the solid catalyst, act as molecular co-catalysts that participate in the critical O–O bond-formation step along with solid sites. This synergistic mechanism, involving both solid and molecular active species, circumvents the typical scaling limitations observed for solid catalysts alone. Our findings reveal an unconventional solid–molecular mechanism that governs electrocatalysis at the solid–liquid interface and suggest a strategy for transcending scaling constraints through cooperative multi-site catalysis.

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Fig. 1: Dynamic behaviour at the electrode–electrolyte interface.
Fig. 2: Dynamic local structural change in Fe species during the OER.
Fig. 3: Interaction between the electrode and the molecular Fe species.
Fig. 4: Mechanistic understanding and schematic illustration of the SMM.
Fig. 5: OER performance of the MNF catalysts with and without the addition of iron gluconate to the electrolyte.

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Data availability

Source data are provided with this paper. The atomic coordinates of the optimized computational models are also provided. Other data that support the findings of this study are available from the corresponding authors upon reasonable request.

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Acknowledgements

The work at Virginia Tech was supported by Department of Chemistry start-up funds and the Institute for Critical Technology and Applied Science (F.L.). F.L. also acknowledges the seedling support from the Virginia Tech College of Science Strategic Initiative in Energy (03400) and the support from the Leo and Melva Harris Faculty Fellowship. L. Liu and H.X. gratefully acknowledge the financial support from the National Science Foundation Chemical Catalysis program (CHE-2102363) (H.X.) and the computational resource provided by Advanced Research Computing at Virginia Tech. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract no. DE-AC02-06CH11357. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under contract no. DE-AC02-76SF00515.

Author information

Author notes

  1. These authors contributed equally: Liping Liu, Anyang Hu.

Authors and Affiliations

  1. Department of Chemistry, Virginia Tech, Blacksburg, VA, USA

    Chunguang Kuai, Anyang Hu, Yuxin Zhang, Dawei Xia & Feng Lin

  2. Department of Chemical Engineering, Virginia Tech, Blacksburg, VA, USA

    Liping Liu & Hongliang Xin

  3. Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA

    Yan Zhang, Dennis Nordlund & Dimosthenis Sokaras

  4. Diamond Light Source, Harwell Science & Innovation Campus, Didcot, UK

    Donato Decarolis & Diego Gianolio

  5. Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA

    Luxi Li

  6. Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA, USA

    Feng Lin

  7. Department of Materials Science and Engineering, Virginia Tech, Blacksburg, VA, USA

    Feng Lin

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  1. Chunguang Kuai
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Contributions

F.L. and C.K. conceived the project. C.K. and F.L. designed the overall experiments. C.K., F.L. and L. Li developed the fluorescence imaging measurements. L. Liu and H.X. conducted the DFT calculations and microkinetic analysis. C.K. synthesized the materials and performed the characterization and electrochemical measurements. C.K. and Yan Zhang performed the soft-XAS and operando hXAS experiments with assistance from D.N. and D.S. The synchrotron XFM and HERFD experiments were performed by A.H., Yuxin Zhang and D.X. under the supervision of F.L. and L. Li. The hXAS measurements for key reference samples were performed by D.D. and G.D. The figures were prepared by C.K., L. Liu, H.X. and F.L., who also wrote the manuscript with assistance from all co-authors. All of the co-authors participated in the scientific discussion and approved the manuscript submission.

Corresponding authors

Correspondence to Chunguang Kuai, Hongliang Xin, Luxi Li or Feng Lin.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–43, Notes 1–8 and Tables 1–3.

Supplementary Data 1

Supplementary structure (CIF) files

Supplementary Data 2

Data for Supplementary Fig. 7.

Source data

Source Data Fig. 1

Dynamic behaviour at the electrode–electrolyte interface.

Source Data Fig. 2

Dynamic local structural change of Fe species during the OER.

Source Data Fig. 3

Interaction between the electrode and the molecular Fe species.

Source Data Fig. 4

Mechanistic understanding and schematic illustration of the SMM.

Source Data Fig. 5

OER performance of the MNF catalysts with and without the addition of iron gluconate to the electrolyte.

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Kuai, C., Liu, L., Hu, A. et al. Dissolved Fe species enable a cooperative solid–molecular mechanism for the oxygen evolution reaction on NiFe-based catalysts. Nat Catal 8, 523–535 (2025). https://doi.org/10.1038/s41929-025-01342-5

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