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.