Au/C catalysts prepared by a green method towards C3 alcohol electrooxidation: A cyclic voltammetry and in situ FTIR spectroscopy study

Gold electrocatalysts seems to be an interesting material for application in Alkaline Fuel Cells (AFC) since several studies have reported the electro-catalytic activity of gold-based catalysts for various heterogeneous catalyzed oxidation reactions like oxidation of small organic molecules. In this paper, we synthesized Au nanoparticles (Au Nps) dispersed onto Vulcan carbon substrate using a straightforward glycerol method in order to study the pathway electro-oxidation of alcohols, like glycerol, 1,2-propanediol and 1-propanol.in alkaline medium. TEM images showed a good dispersion of the gold nanoparticles on the carbon support and the particle mean size ranging from 3 to 14 nm. The structure of gold is face centered cubic (fcc) indicated by XRD and the metal loading was 18% evaluated by EDS technique. Cyclic voltammetry was mainly used to evaluate the electrochemical activity of the Au NPs towards the oxidative transformation of alcohols. Electrochemical results proved that Au/C Nps are more active to oxidize glycerol than 1,2-propanediol and 1-propanol, while higher current density was obtained for the diol. In situ FTIR measurements showed different pathway for each alcohol. For glycerol electro-oxidation, the mean byproducts from reaction were formate and oxalate ions. It was already suggested that gold in alkaline medium oxidized glycerol more promptly than others alcohols. The electro-oxidation of 1,2-propanediol leaded to acetate ion and hydroxyacetone while the in situ FTIR spectrum for electrooxidation of 1-propanol suggests that propanoate is the only the product of 1-propanol electro-oxidation over Au/C. (C) 2014 Elsevier B.V. All rights reserved.