Ammonium Tungstate Prepare Flake Nanometer Tungsten Carbide

flake nanometer tungsten carbide SEM figureflake nanometer tungsten carbide SEM figureFlake nanometer tungsten carbide can provide a large number of surface atoms and active center of reaction, which is an ideal structure of catalyst, therefore, the research about it has been attracting the attention of people all the time. Ammonium metatungstate (AMT) is an important raw material in the tungsten metallurgy industry, especially has important role in the preparation of nanometer materials, special specifications of tungsten powder, tungsten oxide powder and tungsten carbide powder. 
Study has used ammonium metatungstate as the raw material to prepare flake nanometer tungsten carbide (WC), with the steps as follows: 
1. Prepare the ammonium metatungstate and ammonium carbonate precursor culture solution with deionized water at room temperature; 
2. Add the precursor culture into the ethanol solution of surfactant (sodium dodecyl benzene sulfonic acid or hexadecyl trimethyl ammonium bromide), and then join the hydroxylamine hydrochloride after stirring evenly; 
3. Continue to stir well, and then add in the hydrochloric acid (HCl) or ammonia water to adjust the pH value to 4 ~ 8, to obtain the precursor solution; 
4. Carry out a hydrothermal reaction on the precursor solution under the temperature of 150~250°C for 10 to 24 hours, and cool the reactant down to room temperature by standing, after removing the supernatant fluid and drying the product, we can get the sample precursor; 
5. Carry out a carbonization on the precursor in the atmosphere of CH4/H2 under 600~900°C, to finally get the flake nanometer tungsten carbide. 
This method of combining hydrothermal self-assembly synthesis and in situ reduction carbonization technology to prepare flake nanometer tungsten carbide from raw material of ammonium metatungstate (AMT) has the advantages, on the one hand, it effectively avoids the reunion of nanometer WC, and fully enlarges the effective specific surface area of WC; on the other hand, the advantages of nano flake material will be fully used, which can provide a large number of surface atoms and reactive centers, and thus to advantageous to the transmission of carriers from inner to the surface of the catalyst, thereby to improve the catalytic activity of nanometer materials. This kind of flake nanometer tungsten carbide can be used in the electric reduction reaction of nitro compound, as the electric catalyst.