Carbon-supported PdSn and Pd3Sn2 anodes for glucose electrooxidation in alkaline media

PdSn (20 wt.%) and Pd3Sn2 (20 wt.%) nanoparticles supported on Vulcan XC-72 carbon powders are prepared by a modified microwave-assisted polyol method and studied for the reaction of glucose electrooxidation in alkaline media. The as-prepared electrocatalysts are characterized by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Cyclic Voltammetry (CV) and Chronoamperometry (CA). For comparison reasons, Pd/C (20 wt%) is also prepared. According to the CV results, the electrochemical active surface areas (EASA) were in the following order: Pd3Sn2/C > PdSn/C > Pd/C (28.8, 22.8 and 10.3 m2 g-1). It is found that for glucose electrooxidation, at room temperature Pd3Sn2/C exhibited the highest electrocatalytic activity, 3.64 mA cm-2, which is increased up to 5.7 mA cm-2, as the temperature increases to 40 C. The effect of concentration of both electrolyte and glucose on the activity is also studied and it is observed that the increase of the amount of both electrolyte and glucose enhances the rate of glucose electrooxidation. Additionally, from the chronoamperometric results, the diffusion coefficients of glucose are calculated to be 7.9 x 10-5, 3.9 x 10-5 and 4.2 x 10-5 cm2 s for Pd3Sn2/C, PdSn/C and Pd/C, respectively. (C) 2014 Elsevier B.V. All rights reserved.