Journal of Electroanalytical Chemistry, Vol.697, 46-52, 2013
Au/C catalysts promoted with metal oxides for ethylene glycol electro-oxidation in alkaline solution
The Au-based catalysts on metal oxide (MexOy)-promoted carbon supports were prepared by polyvinyl alcohol (PVA) protection method and tested in ethylene glycol electro-oxidation. Three types of MexOy promoters, CeO2, Fe2O3 and RuO2, and different Au:MexOy weight ratios of 1:0.25, 1:0.5 and 1:1 were studied. Highly dispersed Au nanoparticles with the average particle sizes approximately 4 nm were obtained for all the catalysts. The activity and stability of the catalysts towards ethylene glycol electrooxidation in alkaline were investigated via cyclic voltammetry and chronoamperometry, respectively. It was found that the electrocatalytic properties of the promoted catalysts were affected by the type and the Au:MexOy ratio. Both types of Fe2O3- and RuO2-promoted catalysts yielded higher mass-normalized current density than the unpromoted Au/C. The most stable catalyst in a high mass-normalized current density region was Au-RuO2/C at Au:RuO2 ratio of 1:0.25. The RuO2-promoted catalysts were still active even in the potential region where the catalyst surface was fully covered by Au oxide film. In comparison with PtRu/C, the promoted Au catalysts generated higher mass-normalized current density. (C) 2013 Elsevier B.V. All rights reserved.
Keywords:Au/C;Metal oxides;Ethylene glycol electro-oxidation;Promoted-Au catalysts;Alkaline exchange membrane fuel cells