Synthesis of Pt/WO_3-C as Catalyst for Oxygen Reduction Reaction and Its Evaluation of Stability

The WO3-C hybrid materials were prepared by chemical precipitation reaction of hydrochloric and sodium tungstate in carbon suspension.Pt nanoparticles were deposited by microwave-assisted polyol process on WO3-C.Influences of WO3 contents and heat-treatment temperature on the catalytic activity for oxygen reduction and the single proton exchange membrane fuel cell performance were analyzed systematically.X-ray diffraction(XRD),transmission electron microscope(TEM) and energy dispersion spectrometry(EDS) were used to characterize the Pt/WO3-C catalysts.The results show that the optimum content of WO3 is 10wt%,and heat-treatment temperature in N2 flow is 250℃.WO3 presents as monoclinic phase and about 2.77 nm Pt metal crystallites disperse on WO3-C.Cyclic voltammetry and polarization curves of single cells are investigated to measure the electrocatalytic activity.The synergistic catalytic effect is found between Pt and WO3.The Pt/WO3-C catalysts are more active for oxygen reduction than traditional Pt/C.The accelerated potential cycling test and single cell life test indicate that the Pt/WO3-C catalysts possess substantially enhanced stability in comparison with Pt/C catalysts.