Highly efficient and selective electrocatalytic hydrogen peroxide production on Co-O-C active centers on graphene oxide.

Electrochemical oxygen reduction provides an eco-friendly synthetic route to hydrogen peroxide (HO), a widely used green chemical. However, the kinetically sluggish and low-selectivity oxygen reduction reaction (ORR) is a key challenge to electrochemical production of HO 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@GO for simplicity) that act as an efficient and durable electrocatalyst for HO production. This Co@GO electrocatalyst shows excellent electrochemical performance in O-saturated 0.1 M KOH, exhibiting high reactivity with an onset potential of 0.91 V and HO production of 1.0 mg cm h while affording high selectivity of 81.4% for HO. Our combined experimental observations and theoretical calculations indicate that the high reactivity and selectivity of Co@GO for HO 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.