Atomically Dispersed Cu−O 4 Sites: A Simplified Coordination Strategy for Efficient and Durable H 2 O 2 Production

This study evaluated the strategy of employing metals with moderate *OOH adsorption strength (copper) coordinated by high-electronegativity ligands (oxygen) to tune the *OOH binding for selective H 2 O 2 electrosynthesis. A uniform four-coordinated Cu−O 4 single-atom catalyst (Cu-SAO) was synthesized via ligand-assisted pyrolysis. Density functional theory calculations indicated that because of the synergy of weak-oxophilicity metal and strong-electronegativity ligands, the Cu−O 4 motif exhibits optimally attenuated *OOH binding and inhibits O−O bond scission. The Cu-SAO catalyst showed an ORR onset potential of 0.72 V and a H 2 O 2 selectivity of 96.2% in rotating ring-disk electrode tests. In addition, it achieved >90% Faradaic efficiency over 50−500 mA cm −2 and maintained stable H 2 O 2 production for 430 h during flow-cell tests, yielding a high H 2 O 2 yield of up to 47.23 mol g −1 h −1 . This work establishes a facile first-shell coordination strategy to simplify the design of efficient 2e − ORR catalysts and advances practical H 2 O 2 electrosynthesis.