Enhancing Oxygen Reduction Reaction Performance of Fe-Based Catalysts’ Nitrogen-Doped MOF Porous Carbon in Acidic and Alkaline Environments through Strong Metal–Support Interaction

The unique advantages of single-atom catalysts (SACs), including exceptional atom utilization efficiency, distinctive quantum confinement effects, and precisely modifiable electronic configurations, have established them as a leading frontier in electrocatalysis research. These properties make SACs promising candidates for the oxygen reduction reaction (ORR). Nevertheless, the present research predominantly concentrates on single-pH environments, with scarce reports addressing the development of dual-environment catalysts capable of maintaining high performance across both acidic and alkaline conditions. In this investigation, a highly dispersed iron single-atom catalyst (FeSA) was synthesized via a facile pyrolysis strategy using a zeolitic imidazolate framework-8 (ZIF-8) precursor and dopamine as the nitrogen/carbon source. The resultant FeSA demonstrated remarkable ORR catalytic performance, exhibiting half-wave potentials (<i>E</i>_1/2) of 0.85 V (vs RHE in 0.5 M H₂SO₄) and 0.88 V (vs RHE in 0.1 M KOH), respectively. When implemented in zinc-air battery (ZAB) systems, the catalyst exhibited a superior electrochemical performance, achieving a specific capacity of 790 mAh g_Zn^-1 and a peak power density of 221 mW cm^-2. These findings highlight the catalyst's potential for useful applications in systems for converting and storing renewable energy. The dual-environment catalytic capability of this FeSA material represents a significant advancement for single-atom electrocatalysis, addressing a critical gap in current catalyst design paradigms.