Preparation of graphene-supported Pt–Co nanoparticles and their use in oxygen reduction reactions

Electrocatalysts of graphene-supported Pt–Co alloy nanoparticles (Pt–Co/G) were prepared by a simultaneous reduction of mixtures of graphene oxide and Pt (IV), Co (II) ions with ethylene glycol assisted by a microwave and further H2 treatment at 300 °C. As-prepared Pt–Co/G catalysts were characterized by transmission electron microscopy, energy-dispersive X-ray spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy. The Pt–Co binary alloy nanoparticles with a size of 3–8 nm were homogeneously dispersed on the graphene. Compared with the monometallic Pt/G and commercial Pt/C catalysts, the Pt–Co/G catalysts have a high stability and increased electrocatalytic activity that is conducive for the oxygen reduction reaction, suggesting their potential application in fuel cells.