Preparation and electrocatalytic activity of hollow global tungsten carbide with mesoporosity

Tungsten carbide (WC) has an important advantage-a unique to resist very strong catalytic poisons, such as carbon monoxide, hydrocarbons, and hydrogen sulfide, but its catalytic activity is much less than that of platinum metal. How to improve its catalytic activity is the key problem for realization in practical usage and replacement of platinum catalyst in catalysis. Hollow global WC with mesoporosity was fabricated by spray drying sphere miniaturation-gas-solid reaction, used ammonium metatungstate and carbon monoxide as precursors. The samples were characterized by XRD, SEM and EDS, respectively. The results show that the particle of the sample is hollow global WC with mesoporosity. Its crystal phase is WC of hexagonal structure with minor tungsten oxides. The electrocatalytic activity of the sample was analyzed by the approach of powder microelectrode. Hollow global WC with mesoporosity and WC are catalytic active for p-nitrophenol reduction reaction in basic solution. The catalytic activity of hollow global WC with mesoporosity is higher than that of nanosized sphere WC, and much higher than that of sphere WC at the same size of hollow global WC with mesoporosity. It is an efficacious way to improve the catalytic activity of WC by adjusting its morphology and structure with mesoporous hollow globe. (c) 2005 Elsevier Inc. All rights reserved.