Tuning lattice oxygen participation to govern OER activity in metal oxides

The lattice oxygen-mediated mechanism (LOM) is critical for lowering oxygen evolution reaction (OER) overpotential in sustainable energy technologies, yet key gaps remain: little is known about how lattice oxygen participation degree affects activity, or why this degree matters. Herein, we demonstrate, for the first time, a volcano-like relationship between LOM participation and OER performance, confirming higher participation does not mean better activity. Synthesizing nine metal oxides with tuned M-O bonds, and using electrochemical tests validated by DFT, we found that an appropriate degree of participation can optimally balance the intermediate adsorption/desorption processes, minimizing overpotential. Excessive/insufficient participation suppresses efficiency. This work identifies the "optimal participation window" bridges fragmented LOM understanding by linking participation to pathway/performance, and provides actionable design criteria for LOM catalysts. It accelerates development of high-efficiency OER systems, advancing sustainable energy technologies.