Glucose electrooxidation over PdxRh/C electrocatalysts in alkaline medium

Abstract

Carbon Vulcan XC-72R supported PdxRh (x = 1, 2, 3) nanoparticles have been prepared by a modified pulse microwave assisted polyol method and have been studied for glucose electrooxidation in alkaline media. The PdxRh/C electrocatalysts have been characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Cyclic Voltammetry (CV) and Chronoamperometry (CA). The effects of the concentration of electrolyte and glucose as well as of temperature on the activity of glucose electrooxidation have been investigated. According to the CV results, the electro-catalytic activity towards glucose electrooxidation of the investigated catalysts has the following order: PdRh/C > Pd/C > Pd2Rh/C > Pd3Rh/C. It was found that increasing electrolyte's concentration until 1.0 M KOH the current density increases, while higher (>1.0 M KOH) OH- concentrations prevent the adsorption of glucose at the electrode. Moreover, increasing glucose's concentration from 0.02 to 0.5 M the current increases for 0.1, 0.3, 0.5, 1.0 and 2.0 M KOH. Additionally, the increment of temperature enhances glucose electrooxidation until 36.5 degrees C, while for temperatures >36.5 degrees C the catalytic activity decreases. (C) 2013 Elsevier B.V. All rights reserved.