Porous Fe–N-codoped carbon microspheres: an efficient and durable electrocatalyst for oxygen reduction reaction

Electrochemical oxygen reduction is a key process for many energy storage and conversion devices, and finding highly efficient, economical, and durable electrocatalysts to replace the Pt-based catalyst for the oxygen reduction reaction (ORR) is a critical obstacle. In this article, porous Fe–N-codoped materials are obtained by pyrolysis of a defined precursor of polydopamine-coated Fe3O4 as not only template but also nitrogen and iron source. In 0.1 M KOH, the as-prepared catalyst exhibited high ORR activity (onset potential of 0.949 V and half-wave potential of 0.836 V vs. RHE), with excellent electrochemical stability, durability and remarkable tolerance toward methanol. The successful synthesis of porous nanospheres provides a novel way to explore a series of mesoporous metal electrocatalysts for energy conversion.