Synthesis of Mesoporous Fe/N/C Electrocatalyst for Improved Oxygen Reduction Reaction Activity Through CO2-Assisted Pyrolysis

Fe/Nx/C electrocatalysts have appeared as one of the promising non-platinum group metal (non-PGM) electrocatalysts for oxygen reduction reaction (ORR) in energy conversion devices. These non-PGM electrocatalysts Fe/N/C need structural tuning of pores to improve the surface area for high-performance ORR in proton exchange membrane fuel cells. In this report, the specific surface area of poly-melamine-formaldehyde (PMF)-based Fe/N/C electrocatalysts was enhanced without using a template through simple CO2-assisted pyrolysis. The highly porous electrocatalyst exhibited an onion-like graphitic structure and an efficient catalytic activity for ORR, comparable to Pt/C electrocatalyst. At 0.95 VRHE, the mass activity of the PMF-based PMF-Fe/N/C-CO2/Ar electrocatalyst was 63 % that of a commercial Pt/C electrocatalyst. Moreover, the devised fabrication process for the PMF-Fe/N/C electrocatalysts with a high specific surface area can be readily scaled up.