Influence of pyrolysis temperature on oxygen reduction reaction activity of carbon-incorporating iron nitride/nitrogen-doped graphene nanosheets catalyst

Carbon-incorporating iron nitride nanoparticles deposited onto nitrogen-doped graphene nanosheets (FeCN/NG) as an alternative non-noble metal catalyst was successfully synthesized by pyrolysis under an ammonia atmosphere in this study. Influence of pyrolysis temperature on its crystalline structure, oxidative valence, morphology, chemical environment and catalytic activity of each FeCN/NG catalyst was examined by X-ray diffractometer, X-ray absorption near edge spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and rotating ring-disk electrode technique, respectively. The optimally sized FeCN nanoparticles around 10 nm were obtained at a pyrolysis temperature of 700 °C, delivering favorable oxygen reduction reaction (ORR) activity in the acid medium. After the durability test of 2000 cycles, not only the onset potential was not significantly shifted but also more than 80% retention on its ORR activity recorded at 0.5 V was achieved, demonstrating its catalytic stability.