Nanostructure and formation mechanism of Pt-WO₃/C nanocatalyst by ethylene glycol method

Pt-WO₃ nanoparticles uniformly dispersed on Vulcan XC-72R carbon black were prepared by an ethylene glycol method. The morphology, composition, nanostructure, electrochemical characteristics and electrocatalytic activity were characterized, and the formation mechanism was investigated. The average particle size was 2.3 nm, the same as that of Pt/C catalyst. The W/Pt atomic ratio was 1/20, much lower than the design of 1/3. The deposition of WO ₃•xH₂O nanoparticles on Vulcan XC-72R carbon black was found to be very diffi cult by TEM. From XPS and XRD, the Pt nanoparticles were formed in the colloidal solution of Na₂WO₄, the EG insoluble Na₂WO₄ resulted in the decreased relative crystallinity and increased crystalline lattice constant compared with those of Pt/C catalyst and, subsequently, the higher specifi c electrocatalytic activity as determined by CV. The Pt-mass and Pt-electrochemically-active-specifi c-surface-area based anodic peak current densities for ethanol oxidation were 422.2 mA•mg^-1Pt and 0.43 mA•cm^-2Pt, 1.2 and 1.1 times higher than those of Pt/C catalyst, respectively.