MOF-derived methanol-tolerant Fe–N–C catalyst for efficient oxygen reduction reaction in direct methanol fuel cell

Abstract

Pt-based electrocatalysts are recognized as the most effective materials for the oxygen reduction reaction (ORR) in fuel cells. However, their widespread application is hindered by high cost, insufficient stability, and susceptibility to methanol and CO poisoning. Therefore, it is crucial to develop non-precious metal catalysts that are efficient, durable, and tolerant to fuel crossover. Herein, we report a facile synthesis of Fe–N–C catalysts derived from transition metal-doped zeolitic imidazolate frameworks via thermal treatment. In alkaline electrolyte, the obtained catalyst exhibited a half-wave potential of 0.79 V (vs. RHE) for the ORR, only 10 mV lower than that of commercial Pt/C. Moreover, it demonstrated excellent stability with 86.7% current retention after 35,000 s, along with outstanding methanol tolerance. In addition, no significant change in current response was observed upon the addition of 1 M methanol during linear sweep voltammetry. Notably, a direct methanol fuel cell incorporating the Fe–N–C catalyst delivered a peak power density of 13.3 mW cm⁻² at 65 ℃. This work highlights the critical role of Fe single atoms in enhancing both ORR activity and methanol tolerance, underscoring the significance in advancing the development of high-performance electrocatalysts for fuel cell applications.

Graphical abstract

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