Tungsten Hydride Reduction
Introduction
Tungsten hydride reduction is an advantageous method of reducing tungsten oxide (WO3) to metallic tungsten. Reducing tungsten oxide is necessary in order to obtain tungsten in various forms. Tungsten hydroxide is created by reacting tungsten oxide with hydrogen, forming a compound of tungsten (III) oxide and hydrogen (WxHy). Since tungsten oxide has a strong oxide bond, it can only be reduced in a very controlled environment. Tungsten hydride reduction is carried out by a variety of doping agents that supply additional electrons to the system, breaking the oxide bonds and releasing the tungsten element from the oxide. This process leaves the reduced tungsten in a metallic form, which can then be manipulated into many different shapes and sizes for a variety of applications.
Process Description
Tungsten hydroxide is created by reacting tungsten trioxide (WO3) with hydrogen. In the process, hydrogen suspends the lattice of the oxygen in the tungsten oxide and forms a compound of tungsten (III) oxide and hydrogen (WxHy). After the hydrogen reacts with the tungsten oxide, the mixture is then heated to a temperature of 800-900ºC in order to reduce the tungsten oxide. During this process, one or more substances called doping agents are added to provide additional electrons to break the oxide bonds in the tungsten oxide. These doping agents also contribute to the reduction of the tungsten oxide, making them an essential component to the tungsten hydride reduction process.
The doping agents that are used in the tungsten hydride reduction process can be divided into three categories: organics, metal complexes, and metal complexes with electron donors. Organic doping agents are compounds that are made from carbon and hydrogen atoms, and they are a popular choice because they are routinely used in common chemical reactions and can be found in a variety of sources. Metal complexes are created when metal ions bind to a particular molecule, and they are often found in inorganic compounds. Finally, metal complexes with electron donors are compounds that involve the metal ion binding to a specific molecule that provides electrons to the metal in order to reduce the tungsten oxide.
After the doping agent is added to the tungsten oxide and hydrogen mixture, the entire mixture is heated up to 800-900ºC, which is referred to as the ‘reduction temperature’. At this temperature, the electrons from the doping agent break down the oxide bonds in the tungsten oxide, releasing the tungsten atom from the lattice. The released tungsten atom then bonds the hydrogen molecules and forms tungsten hydride, which is in a metallic form. This metallic form of tungsten is then cooled down and can be manipulated into a variety of shapes and forms for a variety of applications.
Conclusion
Tungsten hydride reduction is a beneficial process for reducing tungsten oxide to a more manipulatable form. This process makes use of doping agents, which assist in breaking the oxide bonds in the tungsten oxide and releasing the tungsten atom. The tungsten atom is then formed into a metallic state, which is suitable for a variety of uses. Tungsten hydride reduction is a safe and reliable process, and can be used to reduce tungsten oxide to metallic tungsten.
