People-Oriented Version of Platinum Metal Catalyst -- Nano Tungsten Carbide

In nature, platinum group elements are known as precious metals with gold and silver. Platinum, iridium, rhodium, palladium are found in the platinum metal family. The most important value of platinum is not that it is a white gold jewellery, but that platinum is an important industrial catalyst.

Platinum is very useful, but it is scarce. It is understood that 70% of the world's platinum is produced in South Africa and is expensive, so it often restricts the development and progress of the high-tech industry. Therefore, it is particularly important to find an element that can replace the platinum catalyst.

Tungsten carbide base hard alloy has special corrosion resistance, high hardness, excellent fracture toughness and compressive strength, is the modern industrial teeth. The development of nanocomposite technology and materials has injected new vitality into it. Its field of application has expanded from common tools, molds, wear parts, and wear-resistant coatings to large-scale integrated printed circuit boards with diameters equal to human hair, micro drills, dot matrix printers capable of handling billions of shots, precision tooling, hard-to-cut tooling, high-tough wear parts, geological drill bits, and military weapons, but it is rarely known that nanoscale tungsten carbide has a catalytic performance similar to that of platinum.

The catalytic properties of nanoscale tungsten carbide with platinum group metal can be easily analyzed from the valence electron structure of the atom. In a reducing atmosphere or a specific atmosphere, tungsten metal surface has high carbon chemical bond energy, strongly adsorb and activate molecules in the atmosphere, form carbon metal carbide with carbon, reduce surface energy of metals, and maintain moderate surface energy, allowing for catalytic cycling. In addition, after carbide formation, the carbon atoms will contribute to the d electrons of the four electrons of the outer layer to the tungsten, the same as the elemental platinum of the right shift of four positions in the periodic table, the final effect is that after the carbonization, the electronic properties of tungsten are closer to the platinum group metal, which leads to the catalytic properties of tungsten carbide similar to that of the platinum group metal.

Numerous results show that the surface properties of nano tungsten carbide on its catalytic performance in the hydrocarbon hydrogenolysis reaction, and its hydrogen adsorption process has a great impact. The catalytic action of tungsten carbide on the hydrogenolysis of hydrocarbons is based on the dual functional structure existing on the surface of the tungsten carbide, that is, the acidic center formed by the presence of oxygen on the surface of the tungsten carbide and the metal spots formed by the tungsten carbide. In the process of catalytic hydrocarbon reaction, molecular metal can be strongly adsorbed reactants in hydrogen and hydrocarbons to form their active groups on the surface of tungsten carbide, WO_X acid can promote carbon chain structure changes, generating isomerization products, while preventing the active center of tungsten carbide to make further isomerization products hydrogenolysis.

Thus, with its special platinum-like properties of tungsten carbide is expected to replace platinum as a new generation of aerospace fuel, new energy battery catalyst, through continuous improvement of tungsten carbide powder preparation methods and composite methods, the future of high-end energy materials will become more and more common, and into the tens of thousands of households to replace petrochemical materials.

• < Prev
• Next >