Electro-oxidation of methanol on SnO2-promoted Pd/MWCNTs catalysts in alkaline solution

The methanol electro-oxidation (MEO) on Pd-SnO2/MWCNTs catalysts prepared by microwave-assisted polyol reduction method has been investigated. The structure, morphology and electro-catalytic performances of the catalysts were characterized with XRD, TEM and cyclic voltammetry (CV). The results showed that the highly dispersed Pd nano-particles (PdNPs) with a narrow size distribution on MWCNTs were successfully synthesized. The catalytic activity of Pd-SnO2/MWCNTs for MEO was up to 778.8 mA/mg Pd in 0.1 M KOH solution containing 1 M methanol, which was significant higher than that of Pd/C (414.2 mA/mg Pd) or Pd-SnO2/C (566.7 mA/mg Pd). Moreover, the MEO on Pd-SnO2/MWCNTs electrode displayed an irreversible behavior under a diffusion control giving an exchange current density (j(0)) of 3.76 x 10(-4) A cm(-2) and a Tafel slope of 149 mV dec(-1) (alpha = 0.56) at 25 degrees C, which indicates that Pd-SnO2/MWCNTs catalyst has a high electro-catalytic performance for the MEO in alkaline media. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.