Porous Hierarchical Iron/Nitrogen co-doped Carbon Etched by g-C₃N₄ Pyrolysis as Efficient Non-noble Metal Catalysts for PEM Fuel Cells

Non-noble metal catalysts have captured much attention in the past years for their excellent performance regarding the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). In this research, an iron/nitrogen co-doped carbon synthesized by transforming ZIF-8 regular dodecahedron into hierarchical porous structure using pretreated g-C₃N₄ as etching agent is introduced. The prepared catalyst (Fe-ZIF/CN-UC) exhibited remarkable ORR activity in acidic medium with a half-wave potential of 0.7861 V (only 50 mV lower than that of the commercial Pt/C catalyst). After a 100000 s stability test, the catalytic performance decreased by 11 % (the half-wave potential only loses 32 mV). Moreover, the produced Fe-ZIF/CN-UC electrocatalyst was applied as cathode catalyst of H₂-O₂ PEMFCs and it displays a remarkable performance with current density of 2 A ⋅ cm⁻² at 0.2 V vs. RHE and the maximum power density reaches 0.484 W ⋅ cm⁻².