Confined Ir single sites with triggered lattice oxygen redox: Toward boosted and sustained water oxidation catalysis

Efficient electrocatalysts for oxygen evolution reaction (OER) in acid are critical to the development of clean energy conversion schemes. Lattice-oxygen-mediated mechanism (LOM) has been developed to boost OER kinetic via triggering lattice oxygen redox. However, the promoted intrinsic activity is compromised by low stability due to bulk structure reconstruction during OER. Here, we demonstrate that a single-site Ir-doping strategy can effectively address this challenge. Attributing to the carefully defined chelation environment of Ir, increased Ir–O covalency and engaged lattice oxygen oxidation have been observed. More importantly, locally triggered LOM introduces no structure evolution during OER. As a result, the constructed catalyst (Ir–MnO2) exhibited over 42 times more mass activity than that of commercial IrO2 as well as over 650 h stability with only a 15 mV increase in overpotential. Our work opens up a feasible strategy to boost OER activity and stability simultaneously.