Preparation of tungsten carbide porous sphere core wrapped by porous multiwall

Tungsten carbide porous sphere core wrapped by porous multiwall was prepared by spray drying sphere miniaturation-gas-solid reaction, used ammonium metatungstate as precursors, hydrogen and methane as reduction and carbonization atmosphere. The sample was characterized by SEM, XRD and BET, respectively. The SEM results show that the sample is constituted by two parts, a core with porosity and porous multiwall, and the wall is made up of a lot of nanoscale particles. The XRD results show that the crystal phase of the sample is tungsten carbide (WC) only, and the average size of the WC crystal estimated according to XRD data is around 14 nm. The BET specific area of the sample is 10.2834 m(2)/g. (c) 2006 Elsevier B.V. All rights reserved.