Graphene-Based Non-Noble-Metal Catalysts for Oxygen Reduction Reaction in Acid

Abstract

Non-noble-metal catalysts based on Fe–N–C moieties have shown promising oxygen reduction reaction (ORR) activity in proton exchange membrane fuel cells (PEMFCs). In this study, we report a facile method to prepare a Fe–N–C catalyst based on modified graphene (Fe–N–<i>r</i>GO) from heat treatment of a mixture of Fe salt, graphitic carbon nitride (<i>g</i>-C₃N₄), and chemically reduced graphene (<i>r</i>GO). The Fe–N–<i>r</i>GO catalyst was found to have pyridinic N-dominant heterocyclic N (40% atomic concentration among all N components) on the surface and have an average Fe coordination of ∼3 N (Fe–N_3,average) in bulk. Rotating disk electrode measurements revealed that Fe–N–<i>r</i>GO had high mass activity in acid and exhibited high stability at 0.5 V at 80 °C in acid over 70 h, which was correlated to low H₂O₂ production shown from rotating ring disk electrode measurements.