On September 30, 2025, Professor Wang Chundong and his research team at Huazhong University of Science and Technology published a research paper entitled "Leveraging Co Spin State in Metal–Organic Frameworks for Efficient Water Oxidation" in the renowned journal ACS Catalysis. This research centers on the catalyst-related bottleneck encountered in the oxygen evolution reaction (OER) during water electrolysis, a crucial process in green hydrogen energy production.

The team synthesized a Mn-doped cobalt-based metal-organic framework (MOF) catalyst, designated as CoMnFcMOF, through a straightforward one-step hydrothermal method. This synthesis employed ferrocene-based dicarboxylic acid as the ligand and nickel foam as the substrate. Material characterization unveiled that CoMnFcMOF possesses a two-dimensional layered octahedral coordination structure. It forms dense nanosheets with an average size of around 600 nm, and these nanosheets exhibit a uniform distribution of elements. Notably, Mn was successfully incorporated into the MOF without disrupting its framework, while simultaneously introducing more oxygen defects.

Through magnetic and electronic structure analyses, it was confirmed that Mn doping induced a transition of Co from a high-spin state to an intermediate-spin state. This transition led to a reduction in the total effective magnetic moment. Moreover, the ferrocene groups incorporated in the structure enhanced the electron transport efficiency.

Electrocatalytic performance tests revealed that under alkaline conditions, CoMnFcMOF demonstrated exceptional performance. It exhibited an overpotential of merely 207 mV at a current density of 10 mA·cm⁻² and 238 mV at 100 mA·cm⁻². These values significantly outperformed those of the parent CoFcMOF and commercial RuO₂. Additionally, after 200 hours of continuous electrolysis, there was no significant decline in its activity.

DFT calculations provided a deeper understanding by elucidating the catalytic mechanism of CoMnFcMOF during the OER process. This research offers a novel paradigm of "spin-state engineering" for the design of transition metal-based OER catalysts, opening up new avenues for future catalyst development.