Reduced graphene oxide supported palladium–silver bimetallic nanoparticles for ethanol electro-oxidation in alkaline media

Palladium–silver bimetallic nanoparticles loaded on reduced graphene oxide (Pd–Ag/RGO) were prepared by co-reduction of mixed metal salts and graphene oxide (GO) with urea-assisted ethylene glycol (EG). The as-obtained Pd–Ag/RGO nanocomposites were characterized by X-ray diffraction, transmission electronic microscopy, and UV–Vis absorption spectroscopy. The results show that the nanoparticles with an average particle size of 5 nm are dispersed on the surface of RGO highly uniformly, besides the Pd–Ag bimetallic nanoparticles are more helpful to promote the reduction of GO than monometal ones. The electrochemical activities of the as-prepared nanocomposites for ethanol oxidation were investigated by using cyclic voltammetry and chronoamperometry in alkaline solution. Compared to the Pd–Ag/E-tek carbon (Pd–Ag/C) and Pd–Ag/multi-walled carbon nanotubes (Pd–Ag/MWCNTs) which were fabricated by the same method, the Pd–Ag/RGO exhibit much higher electrocatalytic activity, stronger tolerance to CO and better stability during the ethanol electro-oxidation reaction in alkaline media. The electrocatalytic performances of Pd–Ag/RGO with different mass ratios of Pd–Ag toward ethanol oxidation in alkaline media were also studied. The results indicate that the electrocatalytic activity of Pd–Ag/RGO with 1:1 mass ratio of Pd–Ag is the best.