Interface Engineering Breaks the Activity–Stability Trade-Off in Water Oxidation through Coupled Oxygen Evolution Mechanism

Activating lattice oxygen is widely recognized to enhance the activity of oxygen evolution reaction (OER) catalysts; however, it may accelerate lattice oxygen leaching and thus compromise stability. To address this, we design an AgxO/CoOOH heterogeneous interface to trigger a coupled lattice oxygen evolution mechanism (COM) and further stabilize the heterointerface through Fe doping. The resulting AgFe-CoOOH catalyst exhibits a low overpotential of 220 mV at 10 mA cm–2 during alkaline OER and exhibits minimal decay at nearly 3000 h at 1 A cm–2 in an anion-exchange membrane water electrolyzer (AEMWE). We demonstrate that constructing an AgxO/CoOOH interface enables direct coupling between the oxygen species adsorbed on Ag and the adjacent lattice oxygen of CoOOH; thus, the overpotential significantly drops from 0.96 to 0.22 V. Subsequent Fe doping in CoOOH lowers the oxygen-vacancy formation energy and shifts the O p-band center toward the Fermi level, thus activating lattice oxygen and enhancing interfacial charge interactions, which collectively improve activity and stability. Different from the traditional OER mechanisms, which rely on either metal or oxygen redox centers, our interface engineering strategy realizes the simultaneous activation of metal and oxygen redox centers, enabling the COM pathway, and provides a paradigm for overcoming the activity–stability trade-off in OER catalysts, demonstrating significant potential for industrial water electrolysis.