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

Abstract

The two-electron oxygen reduction reaction (2e⁻ ORR) has become a hopeful alternative for production of hydrogen peroxide (H₂O₂), 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 H₂O₂. 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 H₂O₂ yield rate of 7.32 mol g_cat.⁻¹  h⁻¹ 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.