Novel combustion-carbonization preparation of mesoporous tungsten carbide as a highly active catalyst for oxygen reduction

Abstract

Tungsten carbide (WC) powder was synthesized by a novel combustion-carbonization method. The structure and morphology of WC powder was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results show that a pure phase of WC powder can be obtained at 850 °C, and the particle size of the WC powder is about 30–100 nm. Compared with the conventional calcination-carbonization method, the combustion-carbonization method can obtain WC powder with a larger surface area and carbon coating structure. The results of cyclic voltammetry (CV) and linear sweep voltammetry (LSV) measurement show that the WC catalyst exhibits a defined ORR activity in an alkaline solution and its oxygen reduction peak potential, peak current density, and half-wave potential are −0.36 V, 0.5 mA, and −0.31 V, respectively. The preceding test results proved that WC prepared by this facile method has excellent oxygen reduction catalytic activity.