Ordered mesoporous tungsten carbide nanoplates as non-Pt catalysts for oxygen reduction reaction

We represent well-defined mesoporous tungsten carbide catalysts for oxygen reduction reaction in alkaline solution. The pore structures of tungsten carbide nanoplates (WC-700-m, WC-800-m and WC-900-m) are formed as a function of reaction temperature of 700, 800 and 900 C in CH4((25%)/H-2(75%) atmosphere for 9 h using layered tungsten nitride nanoparticles. All the tungsten carbide nanoplates exhibit isothermal sorption characteristics of mesoporous structure and fairly monomodal pore size distribution in the range of 6.6-7.2 nm. The WC-700-m, WC-800-m, and WC-900-m exhibit X-ray diffraction patterns corresponding to WCi-x, WCi-x +WC, and WC phase, respectively. In particular, the WC-900-m shows highly improved electrocatalytic activity toward oxygen reduction reaction in an alkaline solution as compared to the WC-900-c. Furthermore, the WC-900-m supported Pd catalyst as a non-Pt exhibits much enhanced electrochemical oxygen reduction properties in comparison with conventional Pt catalyst. (C) 2014 Elsevier B.V. All rights reserved.