Nano Tungsten Carbide Synthesis Method

Nano-tungsten carbide powder is an important raw material for superfine cemented carbide. At the same time, nano-tungsten carbide powder has high specific surface area, which is also conducive to improving its catalytic performance and advantages as catalyst carrier. Therefore, the study of nano-tungsten carbide is of great significance.

The synthesis method of nano tungsten carbide can adopt the following scheme:

1.Weigh 10g H₂WO₄ and put it into 1000ml conical bottle. Wet it with 2ml distilled water. Weigh 52g n-octane and 360g n-heptane. Mix them evenly. Add the mixture of amine and alkane into the conical bottle containing tungstic acid, stirring vigorously at the same time, and start to be yellow suspension. As time goes on, the color of the suspension gradually becomes pale. After half an hour, it becomes beige. Now white, stirring for 24 hours, standing for 24 hours.

2.The white suspension was separated from solid and liquid, washed by alcohol five times (3000r/min, 10min) and dried at room temperature and vacuum for 30h. 18G tungstate-based inorganic-organic hybrid layered compounds were obtained.

3.The tungstate-based inorganic-organic hybrid layered compounds obtained from 0.15g were packed into a sealed quartz tube with a diameter of 8mm and a length of 250mm, vacuum to 2 *10-2Pa, and sealed. The sealed quartz tube was placed in a muffle furnace and heated to 750 ℃ at a heating rate of 1 ℃/min for 20h, and cooled naturally to obtain 0.07g tungsten carbide black powder with a yield of 99%.

From the X-ray diffraction analysis, it can be seen that the main phase of the sample is hexagonal tungsten carbide, with a small amount of W₂C, the content of W₂C can be estimated to be about 6%; the size of tungsten carbide particles is about 200 nm, which is a homogeneous porous tungsten carbide sphere with multi-level structure. The single tungsten carbide particles are only about 10-100 nm, and the surface area of BET is about 1-50 m²/g. When used in wear-resistant materials or cutting tools, this structure is conducive to improving the bonding force between reinforcer and matrix materials. When used as catalyst carrier, the developed porous structure and larger specific surface area are conducive to loading more catalysts. The porous microspheres composed of nanoparticles have larger volume and are conducive to recycling. At the same time, large specific surface area and developed pore structure are also conducive to improving the catalytic activity of tungsten carbide materials, which can be directly used as catalysts for fuel cells.

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