Abstract
? 2022 Elsevier B.V.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.
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Elsevier