Electrochemically assisted polymerization synthesis of ZIF-derived Fe-N/C with high oxygen reduction reaction activity

The zeolitic imidazolate framework-8 (ZIF-8)-derived Fe-N/C catalysts show excellent oxygen reduction reactions (ORR) performance, but the harsh synthesis conditions and low yields have greatly limited their commercialization. Herein, we report an electrochemical-assisted polymerization method to produce a Fe-N/C structure (EC-Fe-N/C) with a high surface area (954.583 m2 g-1), high dispersion of Fe (2.2 wt %), and abundant N (2.05 wt %). The hierarchical structure exhibits excellent ORR activity (half-wave potential 0.88 V, in alkaline media) and outstanding zinc-air battery performance (energy density 821.3 mAh g-1 Zn, specific capacity 1017.1 Wh kg-1 Zn). This work may provide a simple and effective strategy to rationally design the Fe-N/C porous structure for highly efficient ORR activity. Atomically dispersed Fe-doped ZIF-8 was synthesized by electrochemical method. The Fe-N/C catalyst obtained after pyrolysis has excellent ORR activity under alkaline conditions and impressing performance after being assembled into an aqueous zinc-air battery. It has outstanding specific capacity of 196.1 mW cm-2 and discharge power density of 1017.1Wh kg-1 Zn. This work provides an effective, green, and sustainable route for the preparation of oxygen reduction catalysts.