A Generalized Coordination Engineering Strategy for Single‐Atom Catalysts toward Efficient Hydrogen Peroxide Electrosynthesis

Abstract

AbstractDesigning non‐noble metal single‐atom catalysts (M‐SACs) for two‐electron oxygen reduction reaction (2e‐ORR) is attractive for the hydrogen peroxide (H2O2) electrosynthesis, in which the coordination configuration of the M‐SACs essentially affects the reaction activity and product selectivity. Though extensively investigated, a generalized coordination engineering strategy has not yet been proposed, which fundamentally hinders the rational design of M‐SACs with optimized catalytic capabilities. Herein, a generalized coordination engineering strategy is proposed for M‐SACs toward H2O2 electrosynthesis via introducing heteroatoms (e.g., oxygen or sulfur atoms) with higher or lower electronegativity than nitrogen atoms into the first sphere of metal‐N4 system to tailor their electronic structure and adjust the adsorption strength for *OOH intermediates, respectively, thus optimizing their electrocatalytic capability for 2e‐ORR. Specifically, the (O, N)‐coordinated Co SAC (Co‐N3O) and (S, N)‐coordinated Ni SAC (Ni‐N3S) are precisely synthesized, and both present superior 2e‐ORR activity (Eonset: ≈0.80 V versus RHE) and selectivity (≈90%) in alkaline conditions compared with conventional Co‐N4 and Ni‐N4 sites. The high H2O2 yield rates of 14.2 and 17.5 moL g−1 h−1 and long‐term stability over 12 h are respectively achieved for Co‐N3O and Ni‐N3S. Such favorable 2e‐ORR pathway of the catalysts is also theoretically confirmed by the kinetics simulations.