Magnetic N-Enriched Fe₃C/Graphitic Carbon instead of Pt as an Electrocatalyst for the Oxygen Reduction Reaction

A series of Fe₃C/C-N_x nanoparticles (NPs) with different nitrogen content are prepared by a simple one-pot route. In the synthetic procedure, aniline and acetonitrile are simultaneously used as the carbon and nitrogen source. The effect of calcination temperature on the structural and functional properties of the materials is investigated. Magnetic measurement shows that the sample prepared at 800 °C (Fe₃C/C-N₈₀₀ NPs) possesses the highest M_s value of 77.2 emu g^-1. On testing as oxygen reduction reaction (ORR) catalysts, the sample prepared at 750 °C (Fe₃C/C-N₇₅₀ NPs) shows the best ORR performance among the series, with a more positive onset potential (+0.99 V vs. RHE), higher selectivity (number of electron transfer n≈3.93), longer durability, and stronger tolerance against methanol crossover than commercial Pt/C catalysts in a 0.1 m KOH solution. Moreover, in acidic solution, the excellent ORR activity and stability are also exhibited. Magnetic nanomaterials: A series of Fe₃C/C-N_x nanoparticles (NPs) with different nitrogen content are prepared by a simple one-pot route (see figure). The materials exhibit excellent magnetic properties and oxygen reduction reaction (ORR) activities.