Electrocatalytic two-electron oxygen reduction over nitrogen doped hollow carbon nanospheres.

The two-electron oxygen reduction reaction (2e ORR) has become a hopeful alternative for production of hydrogen peroxide (HO), but its practical feasibility is hindered by the lack of efficient electrocatalysts to achieve high activity and selectivity. Herein, we successfully synthesized outstanding nitrogen doped hollow carbon nanospheres (NHCSs) for electrochemical production of HO. In 0.1 M KOH, NHCSs exhibit superior and sustained catalytic activity for the 2e ORR with an unordinary selectivity of 96.6%. Impressively, such NHCSs manifest an ultrahigh HO yield rate of 7.32 mol g  h and a high faradaic efficiency of 96.7% at 0.5 V in an H-cell system. Density functional theory calculations were performed to further reveal the catalytic mechanism involved.