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چکیده
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The energy crisis heightens interest in proton exchange membrane fuel cells (PEMFCs), where the oxygen reduction reaction (ORR) is a critical cathodic process hindered by its intrinsic sluggish kinetics. Single-atom catalysts (SACs) at the molecular level, notably those featuring an Fe-N4 structure derived from iron phthalocyanine (FePc), exhibit significant potential but confront the challenges of aggregation and inadequate electrical conductivity. Herein, we present a novel FePc coupled with defect-rich CoNx-doped hollow carbon nanostraw derived from cobalt-doped indium-based metal–organic frameworks (MOFs). This enhancement is attributed to the CoNx structure’s effective modulation of the Fe-N4 active sites, further complemented by the hollow nanostraw structure, which significantly increases the accessibility of active sites, thereby promoting enhanced catalytic performance. FePc@HCoNC demonstrates exceptional ORR performance with an oxygen reduction potential of 0.903 V, half-wave potential of 0.914 V, and limiting current density of 5.18 mA cm−2. For zinc-air batteries (ZABs), FePc@HCoNC achieves an open-circuit voltage of 1.524 V, peak power density of 153.06 mW cm−2, specific capacity of 758.10 mAh g−1, and stable cycling for 150 h. These findings underscore its potential as a superior alternative to precious metal-based catalysts, offering a pathway to more sustainable and efficient energy conversion technologies.
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