Ordered Porous Nitrogen-Doped Carbon with Atomically Dispersed Fen4 for Efficient Oxygen Reduction Reaction in Microbial Fuel Cell

Developing cost-effective platinum group materials (PGM)-free cathode catalysts for the oxygen reduction reaction (ORR) to replace the state-of-the-art noble metal is essential for the commercialization of microbial fuel cells (MFCs). Fe-N-C catalysts are regarded as one of promising candidates to commercial Pt/C. Herein, a new cost-effective and highly stable Fe-N-C catalyst was designed and successfully prepared by a simple and feasible process. It was prepared through one single thermal conversion from Fe-doped ZIF-8, a metal-organic framework (MOF) containing Zn 2+ and well-defined Fe-N 4 coordination.The mesopores resulting from the unique structure of MOF promote the efficient mass transfer, while the micropores arising from the pyrolysis of the MOF produce more active sites and therefore effective for ORR. Unlike other Fe-N-C catalyst preparation, this work did not need any tedious post-treatments such as acid washing and the second heating treatment. As a result, the Fe-N-C cathode exhibits a high ORR activity with a half-wave potential (E 1/2 ) of 0.85 V in a 0.1 M KOH aqueous solution. Furthermore, the microbial fuel cells (MFCs) with Fe-N-C cathode also provide a maximum power density to 1508 mW m -2