WO3 Modified Graphene Supported Pt Electrocatalysts with Enhanced Performance for Oxygen Reduction Reaction

To improve performance of Pt catalyst, the unique Pt/WO3-G catalysts for oxygen reduction reaction (ORR) are prepared, in which WO3 modified graphene (WO3-G) is adopted as a carrier. According to XRD experiment results, Pt/WO3-G catalysts are primarily composed of Pt nanoparticles, monoclinic WO3 and graphene. The TEM and high resolution TEM analysis indicate that Pt/WO3-G catalyst with the coexistence of Pt particles and WO3 has narrower distribution of Pt particles with average particle size of 3.9 nm. As expected, The Pt/WO3-G catalysts reveal better electrocatalytic activity with higher current densities, lower overpotential and faster kinetics process compared to the Pt/G catalyst. The enhancement of ORR activity on Pt/WO3-G electrocatalyst is probably attributed to the synergistic effect between Pt and WO3 nanoparticles. Specifically, the interaction between Pt and WO3 can increase the dispersion of Pt nanoparticles, accelerate the protonation of the O-2 molecule and decrease the adsorption strength of oxygenated species.