Simple and efficient deposition of Pd nanoparticles on Fe3O4 hollow nanospheres: A new catalytic system for methanol oxidation in alkaline media

An efficient, low-cost and general strategy is developed to deposit well-dispersed Pd nanoparticles on Fe3O4 hollow nanospheres. In this route, Fe3O4 hollow nanospheres pretreated with dilute HCl solution were firstly employed as supports and simple chemical reduction was then introduced. The morphology, structure and elemental composition of the as-obtained samples were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM), X-ray energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), nitrogen sorption and elemental analysis. Electrodes coated with the Pd/Fe3O4 were studied for the oxidation of methanol in 0.1 M NaOH in half cells. The results show highly dispersed Pd nanoparticles are evenly immobilized on the surface of Fe3O4 hollow nanospheres. The cyclic voltammetry tests reveal this novel composite possesses excellent electrocatalytic activity and long-term stability for methanol oxidation in alkaline media.