Enriched graphitic N-doped carbon-supported Fe3O4 nanoparticles as efficient electrocatalysts for oxygen reduction reaction

Abstract

Graphitic N is proposed to be one of the most likely active sites for the oxygen reduction reaction (ORR) in N-doped carbon materials. However, the recent hybrid composites consisting of N-doped carbons and transition metal oxides for the ORR are predominantly pyridinic N- and pyrrolic N-doped carbon-supported cobalt or manganese oxides. Here, an enriched graphitic N-doped carbon-supported Fe₃O₄ nanoparticles composite was prepared via a solvothermal carbonization process. The hybrid composite exhibits a similar high catalytic activity with the 4e⁻ reaction pathway but superior stability to Pt/C for the ORR in alkaline media. Furthermore, the composite also shows a better ORR performance than previously reported transition metal oxides-based N-doped carbon hybrid composites. The unusual high catalytic activity arises from the combination of the high surface area and the synergetic coupling effect between the enriched graphitic N-doped carbon and Fe₃O₄ nanoparticles.