▎ 摘　　要

Hydrogen peroxide is an industrially highly demanded chemical, but its electrochemical synthesis still suffers from sluggish kinetics and imperfect selectivity. Here, the authors report a catalyst material comprising single cobalt atoms anchored on oxygen functionalized graphene oxide that produces 1.0 mg cm(-2) h(-1) of H2O2 with high selectivity and a low onset potential. Electrochemical oxygen reduction provides an eco-friendly synthetic route to hydrogen peroxide (H2O2), a widely used green chemical. However, the kinetically sluggish and low-selectivity oxygen reduction reaction (ORR) is a key challenge to electrochemical production of H2O2 for practical applications. Herein, we demonstrate that single cobalt atoms anchored on oxygen functionalized graphene oxide form Co-O-C@GO active centres (abbreviated as Co-1@GO for simplicity) that act as an efficient and durable electrocatalyst for H2O2 production. This Co-1@GO electrocatalyst shows excellent electrochemical performance in O-2-saturated 0.1 M KOH, exhibiting high reactivity with an onset potential of 0.91 V and H2O2 production of 1.0 mg cm(-2) h(-1) while affording high selectivity of 81.4% for H2O2. Our combined experimental observations and theoretical calculations indicate that the high reactivity and selectivity of Co-1@GO for H2O2 electrogeneration arises from a synergistic effect between the O-bonded single Co atoms and adjacent oxygen functional groups (C-O bonds) of the GO present in the Co-O-C active centres.