Dumbbell-like Pt-Fe3O4 Nanoparticles and Their Enhanced Catalysis for Oxygen Reduction Reaction

Monodisperse dumbbell-like Pt-Fe3O4 nanoparticles are synthesized by epitaxial growth of Fe onto Pt nanoparticles followed by Fe oxidation. The nanoparticle size in the structure is tunable from 2 to 8 nm for Pt and 6 to 20 nrn for Fe3O4. Pt nanoparticles in the pt-Fe3O4 structure show a 20-fold increase in mass activity toward oxygen reduction reaction compared with the single component Pt nanoparticles and the commercial 3 nm Pt particles. The work proves that it is possible to maximize catalytic activity of the Pt nanoparticle catalyst through the control not only of Pt size and shape but also of its interaction with Fe3O4 nanoparticles.