Maximizing the platinum utilization in electrocatalysts toward oxygen reduction reaction (ORR) is very desirable for large-scale sustainable application of Pt in energy systems. A cost-effective carbon-supported carbon-defect-anchored platinum single-atom electrocatalysts (Pt1 /C) with remarkable ORR performance is reported. An acidic H2 /O2 single cell with Pt1 /C as cathode delivers a maximum power density of 520 mW cm-2 at 80 °C, corresponding to a superhigh platinum utilization of 0.09 gPt kW-1 . Further physical characterization and density functional theory computations reveal that single Pt atoms anchored stably by four carbon atoms in carbon divacancies (Pt-C4 ) are the main active centers for the observed high ORR performance.

Carbon‐Supported Divacancy‐Anchored Platinum Single‐Atom Electrocatalysts with Superhigh Pt Utilization for the Oxygen Reduction Reaction