Rational engineering of iron phthalocyanine‐derived single atom catalysts for anion exchange membrane fuel cells

Abstract Anion exchange membrane fuel cells (AEMFCs), which operate in alkaline environments, offer advantages such as compatibility with non‐precious metal catalysts such as Fe‒N‒C, making them an alternative to Pt‐based systems. This study explores development of iron phthalocyanine (FePc)‐derived Fe‒N‒C catalysts for AEMFCs, focusing on optimizing oxygen reduction reaction (ORR) activity and durability. The Fe‒N‒C/C catalysts were synthesized by pyrolyzing FePc supported on carbon (FePc/C) precursors at varying temperatures (500°C–900°C), followed by acid washing. High‐angle angular dark field scanning electron microscopy confirmed the atomic dispersion of Fe species, while X‐ray photoelectron spectroscopy analysis revealed the impact of pyrolysis temperature on active site configuration. The Fe‒N‒C/C catalyst heat treated at 600°C exhibited an optimal balance of Fe atomic content and pyrrolic‐N, resulting in superior ORR performance with a half‐wave potential ( E 1/2 ) of 0.882 V, surpassing commercial Pt/C. Durability tests demonstrated minimal losses (3 mV in E 1/2 ) after 20 000 cycles, emphasizing the strong coordination of Fe‒N x sites with the carbon matrix. In single‐cell tests, the Fe‒N‒C/C catalyst exhibited promising performance comparable to that of commercial Pt/C in the high‐operating voltage region. These findings highlight the potential of Fe‒N‒C catalysts as cost‐effective, durable catalysts for AEMFCs.