Design of Fe/Co-N doped porous carbon sheets by hard template strategy as an oxygen reduction catalyst for Mg-air batteries

The commercialization of magnesia-air batteries (Mg-air) necessitates the development of highly efficient, cost-effective, and durable electrocatalysts for oxygen reduction reaction (ORR), replacing expensive and unstable precious metal electrocatalysts. A hard template-assisted synthesis of FeCo nanoparticles immobilized on N-doped porous carbon (Fe-Co-C-N) for the ORR is reported. The half-wave potential of Fe-Co-C-N for ORR (E1/2=0.88 V vs. RHE) is elevated by 40 mV compared to that of 20 wt% Pt/C (E1/2=0.84 vs. RHE). The catalyst exhibits exceptional catalytic performance and remarkable stability. The discharge voltage of the Mg-air battery, utilizing Fe-Co-C-N as the cathode catalyst (1.29 V), surpasses that of the battery employing 20 wt% Pt/C as the cathode catalyst (1.28 V). The Mg-air battery with Fe-Co-C-N as the cathode catalyst exhibited excellent discharge stability and maintained a stable discharge for over 200 hours. The present study offers valuable insights into the structural design and regulatory mechanisms governing the performance of M-N-C catalysts in Mg-air batteries.