Journal of Power Sources, Vol.196, No.5, 2621-2626, 2011
Pt nanoparticles supported on WO3/C hybrid materials and their electrocatalytic activity for methanol electro-oxidation
A simple and novel method for the preparation of WO3/C is presented. This method includes the adsorption and decomposition of phosphotungstic acid (PWA) on carbon. For the purpose of comparison, WO3/C is also prepared by a conventional method using sodium tungstate as the precursor. These two WO3/C species are denoted as WO3/C-1 and WO3/C-2, respectively. It is shown from transmission electron microscopy (TEM) that the WO3 particles in WO3/C-1 present a more even distribution and smaller particle size than those in WO3/C-2. Pt particles dispersed on WO3/C-1 display the characteristic diffraction peaks of Pt in the face-centered cubic phase. Cyclic voltammetry and chronoamperometry show that the Pt-WO3/C-1 catalyst exhibits much better methanol oxidation activity than the Pt-WO3/C-2 and Pt/C catalysts. This significant improvement in catalytic performance may be attributed to the hydrogen spillover effect and the uniform distribution of Pt and WO3 particles. (C) 2010 Elsevier B.V. All rights reserved.
Keywords:Direct methanol fuel cell;Methanol electro-oxidation;Phosphotungstic acid;Tungsten trioxide