Robust electronic coupling of carbon nanoboxes with synergetic CoFe Alloy nanoparticles boosting efficient electrocatalytic oxygen reduction

The atomically interfacial engineering combined with the rational architecture design is of significant important for developing promising oxygen electrocatalysts towards efficient energy-related applications, but still remains a grand challenge. Herein, we report numerous CoFe alloy nanoparticles, with tunable compositions, anchored firmly over the well-designed oxygen-dopants-rich carbon nanoboxes (CoFe@C NBs) as an active electrocatalyst for electrochemical oxygen reduction reaction (ORR), which is fabricated via a facile cation exchange and pyrolysis strategy. Thanks to the robust interfacial electronic coupling and the highly-exposed synergetic bimetallic centers, this optimized CoFe-27 @C NBs with the Co: Fe atomic ratio of 5.4: 1 could exhibit superior activity, excellent long-term stability and high methanol tolerance during a long-term ORR operation, with an excellent half-wave potential of 0.90 V and decent limiting current density of 5.4 mA cm−2, comparable with the commercial Pt/C catalysts and being one of the most active transition-metal ORR electrocatalysts developed. By the atomic-level synchrotron radiation characterizations and the detailed electrochemical measurements, it can be found that the strong electronic coupling at the metal-support interface could effectively promote the charge transfer and catalytic reaction kinetics, contributing to efficient 4e- ORR for CoFe-27 @C NBs.