MOF-derived two-dimensional FeNx catalysts based on hexamethylenetetramine for efficient oxygen reduction reactions

Although it remains a serious concern, it has become possible to create electrocatalysts that are cheap, effective, and steady for use in oxygen reduction reactions . Herein, we prepared a Fe-doped single-atom porous nitrogen-carbon catalyst by stepwise pyrolysis . The presence of FeN 4 active sites in FeNC-950–2 was confirmed by X-ray absorption spectroscopy (XAS). According to electrochemical tests, FeNC-950–2 outperformed most ORR catalysts and Pt/C in terms of ORR activity in an alkaline environment. The Zinc–air battery constructed with FeNC-950–2 delivers a peak power density of 176.4 mW cm −2 . It also possesses a cycling stability of nearly 300 h. The results demonstrate that the excellent ORR activity is due to the abundant nitrogen doping, graded porous structure, and abundant FeN 4 active sites.