Tungsten nitride decorated carbon nanotubes hybrid as efficient catalyst supports for oxygen reduction reaction

Catalysts for oxygen reduction reaction (ORR) are crucial for the commercialization of proton exchange membrane fuel cells. In this work, nanocrystal tungsten nitride decorated carbon nanotubes hybrid (WN/CNTs-M) introduced as Pt catalyst supports (Pt-WN/CNTs-M) is reported for the first time. X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) measurements are adopted to investigate the physicochemical properties of the prepared catalysts. Cyclic voltammetry and rotating disk electrode techniques are employed to study their corresponding electrocatalytic properties. The results demonstrate that the prepared Pt-WN/CNTs-M catalysts exhibit significantly improved activity toward ORR in acid aqueous solutions, which also display better stability in comparison with the other catalysts in the present study. The reason could be predominantly ascribed to the synergistic effect between tungsten nitride and Pt in the Pt-WN/CNTs-M catalysts and the nitrogen-doping effect of carbon nanotubes with ammonia. The tungsten nitride decorated carbon nanotubes hybrid might be a promising alternative for low-Pt or non-Pt catalysts for oxygen reduction. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.