Studies of the reaction products resulted from glycerol electrooxidation on Ni-based materials in alkaline medium

Abstract

In this work, nickel oxy-hydroxide was shown as active catalytic specie for the glycerol oxidation reaction in alkaline medium. As the formation of cobalt and iron oxy-hydroxides occurs at lower potentials than those of nickel, cobalt and iron amounts were added to modify the Ni material. Carbon supported Ni-M (M=Co, Fe) nanomaterials were thereby synthesized by the impregnation method with metal loadings of wt. 20% and heat-treated in reducing H2 atmosphere. Physical characterizations of the materials were performed with TGA-DTA and XRD to assess their metallic charge and the crystallite size, respectively. Cyclic voltammetry was mainly used to evaluate the electrochemical activity of the catalysts towards the oxidative transformation of glycerol. In a selected potential chronoamperometry experiments were then carried out and the glycerol oxidation products on the Ni-based anodes were analyzed with liquid chromatography. The glycerol conversion depends on the catalyst composition and the distribution of the products was well correlated with those identified with infrared reflectance spectroscopy which supported the proposed simplified mechanism.