Scalable Synthesis of Micro-Mesoporous Iron-Nitrogen Doped Carbon as Highly Active and Stable Oxygen Reduction Electrocatalyst

Micromesoporous metal-nitrogen-doped carbons have attracted incremental attention owning to their high activities for the electrocatalyzing oxygen reduction reaction (ORR). However, scalable synthesis of micromesoporous metal-nitrogen-doped carbons having superior electrocatalytic activity and stability remains a challenge. Here, an iron-nitrogen-doped carbon with highly electrocatalytic properties was simply prepared by ZnCl2 activation of an in situ polymerized iron-containing polypyrrole (PPy@FeClx) at high temperature. High yields of polypyrrole (∼98 wt %) and iron-nitrogen-doped carbon (∼47 wt %) could be reached. The eutectic state of FeClx-ZnCl2 and its derived ZnFe2O4 maskant played important roles in making micromesopores, scattering iron atoms, and trapping nitrogen atoms, leading to numerous micromesopore defects, a larger specific surface area, a more nitrogen doping content, and active sites for the material. The electrochemical tests and Zn–air battery measurements showed that the micromesop...