Engineering Abundant Mesopores in FeNC Single‐Atom Catalysts via High‐Gravity for High‐Performance Oxygen Reduction Reaction

ABSTRACT

The performance of FeNC single atom catalysts (SACs) is significantly influenced by the porous architecture of their N‐doped carbon substrates. Although the pore structure of FeNC SACs has been widely investigated from a chemical methodology perspective, the role of synthesis process engineering has received much less attention. To address this, high‐gravity technology is introduced during the precursor preparation stage to achieve intensive molecular mixing. This approach successfully yields FeNC SACs with a well‐defined hierarchical micro‐mesoporous structure. The resulting catalyst exhibits a narrower mesopore size distribution (4–6 nm), a higher specific surface area (800.3 m ² ·g ⁻¹ ), and a more positive half‐wave potential (0.899 V) for the oxygen reduction reaction (ORR) compared to a reference sample produced in a conventional stirred tank reactor. Density functional theory (DFT) analysis further indicates that the abundant mesopores induce carbon defects, thereby enhancing the intrinsic ORR activity. Moreover, when integrated into a zinc‐air battery and an anion‐exchange membrane fuel cell, the catalyst delivers high peak power densities of 259.5 and 860 mW·cm ⁻² , respectively, highlighting its potential for practical applications.