Boosting Oxygen Reduction for High-Efficiency H₂O₂ Electrosynthesis on Oxygen-Coordinated Co-N-C Catalysts

Atomically dispersed Co-N-C is a promising material for H₂O₂ selective electrosynthesis via a two-electron oxygen reduction reaction. However, the performance of typical Co-N-C materials with routine Co-N₄ active center is insufficient and needs to be improved further. This can be done by fine-tuning its atomic coordination configuration. Here, a single-atom electrocatalyst (Co/NC) is reported that comprises a specifically penta-coordinated Co-N-C configuration (O-Co-N₂C₂) with Co center coordinated by two nitrogen atoms, two carbon atoms, and one oxygen atom. Using a combination of theoretical predictions and experiments, it is confirmed that the unique atomic structure slightly increases the charge state of the cobalt center. This optimizes the adsorption energy towards *OOH intermediate, and therefore favors the two-electron ORR relevant for H₂O₂ electrosynthesis. In neutral solution, the as-synthesized Co/NC exhibits a selectivity of over 90% over a potential ranging from 0.36 to 0.8 V, with a turnover frequency value of 11.48 s⁻¹; thus outperforming the state-of-the-art carbon-based catalysts.