Engineering Asymmetric Electronic Structure of Co─N─C Single‐Atomic Sites Toward Excellent Electrochemical H₂O₂ Production and Biomass Upgrading

Abstract To advance electrochemical H 2 O 2 production and unravel catalytic mechanisms, the precise structural coordination of single‐atomic M‐N‐C electrocatalysts is urgently required. Herein, the Co─N 5 site with an asymmetric electronic configuration is constructed to boost the two‐electron oxygen reduction reaction (2e − ORR) compared to symmetric Co─N 4 , effectively overcoming the trade‐off between activity and selectivity in H 2 O 2 production. Both experimental and theoretical analyses demonstrate that breaking the symmetry of Co─N sites promotes the activation of O 2 molecules and moderates the adsorption of the key *OOH intermediate by disrupting the linear scaling relationship for intermediates adsorption. This modulation enables efficient H₂O₂ production and its effective retention for subsequent applications. As a proof of concept, Co─N 5 achieves a H 2 O 2 production rate as high as 16.1 mol g cat −1 h −1 in a flow cell, outperforming most recently reported counterparts. Furthermore, the coupling of 2e − ORR with the oxidation of cellulose‐derived carbohydrates accomplishes high formic acid yields (84.1% from glucose and 62.0%–92.1% from other substrates), underpinning the sustainable electro‐refinery for biomass valorization at ambient conditions. By elucidating the intrinsic relationship between 2e⁻ ORR and the asymmetry of single‐atomic sites, this work paves the way for high‐performance electrosynthesis.