Study of Nano-WO3 Modified Carbon Nanotubes Supported Pt Electrocatalyst for Oxygen Reduction Reaction

Nano-WO3 modified carbon nanotubes (CNTs), which are prepared by adsorption and decomposition of ammonium metatungstate (AMT) on the surface of CNTs, can act as efficient supports for the Pt electrocatalysis of oxygen reduction reaction (ORR) in acid electrolyte. According to XRD, TEM and HRTEM results, Pt particles are deposited homogeneously on the surface of CNTs with the average size of 2.2 nm. The Pt/WO3-CNTs catalysts exhibit better catalytic activity with higher current densities and lower overpotential comparing to the Pt/CNTs catalyst. The enhancement of ORR activity on Pt/WO3-CNTs electrocatalyst is probably due to the synergistic effect between Pt and WO3 nanoparticles. Specifically, the interaction between Pt and WO3 can increase the dispersion of Pt nanoparticles and decrease the adsorption strength of oxygenated species. In addition, a bronze route mechanism is considered to promote ORR. Moreover, the rotating disk electrode measurements suggest that a 4-electron reduction process takes place on the catalyst surface. Nano-WO3-modified CNTs supported Pt electrocatalysts with low cost and unique activity for ORR, are favorable for potential applications in the cathode of fuel cells.