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 FeN4 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 FeN4 active sites.