Tungsten nitride is a kind of new catalytic material, which shows an excellent performance in hydrogenated desulfurization and denitrification; also, it can not only prevent the sulfur pollution caused by industrial catalyst presulfurization, but also have high selectivity in the hydrogenolysis of heteroatomic ring. 

 

The main preparation method is to get tungsten oxide precursor by sol-gel, spray pyrolysis, rotary kiln calcination method and other methods, and then get a nitridation by inletting ammonia gas. There is a new method to prepare nano tungsten nitride, which is directly using ammonium metatungstate (AMT) as raw material to manufacture the particle size controllable of tungsten nitride with excellent catalytic performance. The preparation process is as following:

1. Prepare a suitable amount of ammonium metatungstate, ammonium nitrate, auxiliary agent and ethylenediamine tetraacetic acid as the raw materials, and get them uniformly dissolved in the water in accordance with a certain proportion; wherein, the molar ratio of ammonium nitrate and tungsten source maybe 12 ~ 36; the molar ratio of adjuvant and tungsten source may be 5 ~ 15; the molar ratio of ethylenediamine tetraacetic acid and tungsten source may be 0.5 ~ 1; 

2. Heat the raw materials’ aqueous solution, and intense REDOX reaction will occur and generate the precursor powder of violet tungsten oxide; 

3. Calcine precursor powder obtained in step 3 under 650 ° C to 900 ° C in the ammonia atmosphere for 1 ~ 2 hours to finally get nanometer tungsten nitride powder. 

 

This method for manufacturing nanometer tungsten nitride from ammonium metatungstate has the following advantages: 

1. Short and simple process, low cost, which make it suitable for mass production; 

2. By controlling the kinds and ratio of raw materials, the reaction process of getting precursor can be well controlled, and further to control the particle size, pore structure of the precursor; 

3. The precursor powder of violet tungsten oxide has high reactivity which will decrease the temperature of heat treatment, and increase the speed of it;

4. By controlling the nitriding temperature to further control the tungsten nitride particle size, pore structure, and eventually improving the catalytic performance of the product.