Electrocatalytic activity of nanostructured Ni and Pd-Ni on Vulcan XC-72R carbon black for methanol oxidation in alkaline medium

Ni and Pd-Ni nanoparticles were chemically deposited on Vulcan XC-72R carbon black by impregnation method using NaBH4 as a reducing agent. The prepared electrocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). The electrocatalytic activity of Ni/C and Pd-Ni/C electrocatalysts towards methanol oxidation in 0.5 M KOH solution was examined using cyclic voltammetry and chronoamperometry. Two methanol oxidation peaks were observed on the Pd-Ni/C at 0 and +860 mV. Their current density values are higher than those at Pd/C and Ni/C electrocatalysts by 1.92 and 1.68 times, respectively. The catalytic rate constant of methanol oxidation reaction at Ni/C and Pd-Ni/C electrocatalysts in (0.2 M MeOH + 0.5 M KOH) solution was estimated using double-step chronoamperometry as 5.64 x 10(3) and 6.25 x 10(3) cm(3) mol(-1) s(-1), respectively. Pd-Ni/C is more stable than Pd/C and Ni/C electrocatalysts. Therefore, Pd-Ni/C is a suitable as a less expensive electrocatalyst for methanol oxidation in alkaline medium. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.