Synthesis of nanocrystalline hexagonal tungsten carbide via co-reduction of tungsten hexachloride and sodium carbonate with metallic magnesium

Nanocrystalline tungsten carbide (WC) was synthesized via a simple route by the reaction of metallic magnesium with sodium carbonate and tungsten hexachloride in an autoclave at 600 °C. X-ray powder diffraction pattern indicated that the product was hexagonal WC, and the cell constant was a = 2.913 Å, c = 2.838 Å. Transmission electron microscopy image showed that it consisted of particles with an average size of 20 nm. The product was also studied by BET and TGA. It had good thermal stability and oxidation resistance below 500 °C in air.