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.