Pomegranate‐Like FeNC with Optimized FeN₄ Configuration as Bi‐Functional Catalysts for Rechargeable Zinc‐Air Batteries

Abstract

Abstract Catalysts with FeNC moieties have demonstrated remarkable activity toward oxygen reduction reaction (ORR), but precise synthesis and configuration regulation of FeNC to achieve bi‐functional catalytic sites for ORR and oxygen evolution reaction (OER) remain a great challenge. Herein, a pomegranate‐like catalyst with optimized FeN 4 configuration is designed. The unique framework affords a large surface area for sufficient active site exposure and abundant macroporous channels for mass transport. By twisting chemical bonds, the electronic structure of FeN 4 is regulated, and the adsorption/desorption of oxygen species is facilitated. Compared to noble metal‐based catalysts (Pt/C+IrO 2 ), the optimized FeNC exhibits impressive onset potential (0.96 V versus reversible hydrogen electrode), larger limiting current density (5.85 mA cm −2 ), and better long‐term life for ORR, as well as, lower OER overpotential. When integrated into Zn‐air batteries, it demonstrates a respectable peak power density (71.6 mW cm −2 ) and ideal cycling stability (30 h), exceeding that of commercial Pt/C+IrO 2 . The exploration offers a guideline for designing advanced bi‐functional electrocatalysts.

Topics & Concepts