Scientists from Tomsk Polytechnic University have developed a new technology for producing high-purity cubic tungsten carbide.
This promising material can replace expensive platinum catalysts for producing hydrogen fuel and thereby reduce its cost. The research results are published in the Journal of Alloys and Compounds (IF: 4.65; Q1). The journalists of the federal agency RIA Novosti told in more detail about the work of Tomsk polytechnics .
Hydrogen is widely used in oil refining and fertilizer production. In addition, it is a promising environmentally friendly fuel that, when burned, releases a large amount of energy and forms water without emitting any harmful gases. The advantages of using hydrogen are obvious, but scientists and engineers still have to solve many problems for the full-scale introduction of hydrogen technologies into the energy sector. One of them is to reduce the cost of producing hydrogen. It remains high, among other things, because the technology uses catalysts made from platinum group metals.
High purity cubic tungsten carbide is a promising material for this application. It is very difficult to obtain under normal conditions: synthesis requires a temperature of about 3000 ° C and a high cooling rate. A team of scientists led by Aleksandr Sivkov, Professor of the Department of Electric Power and Electrical Engineering of TPU, managed to obtain this material of high purity (up to 95%) thanks to a unique installation developed at the Polytechnic Institute.
This is a coaxial magnetoplasma accelerator. It achieves high temperatures and rapid cooling with ultra-fast plasma jets. Available and relatively cheap powders of tungsten and carbon black are used as starting materials, which are preliminarily placed in an accelerator. When the plasma jet flows into the working chamber, the initial powders are converted into cubic tungsten carbide during the plasma-chemical reaction.
According to Ivan Shanenkov , associate professor of the TPU Department of Electric Power and Electrical Engineering , the features of plasma- dynamic synthesis (creation of ultrafast plasma jets of more than 3 km / s, high cooling rate, pulsed nature of the process lasting less than 1 ms) make it possible to form nanoscale (less than 70 nm) particles of cubic tungsten carbide in carbon shells.
“Such structures are successfully used in the reaction of obtaining hydrogen from water by means of electrocatalysis. This will allow minimizing the use of rare and expensive precious metals of the platinum group, ”said Ivan Shanenkov.
He noted that several research teams around the world are engaged in the task of synthesizing composite materials based on cubic tungsten carbide. The development of a plasmodynamic synthesis method made it possible to overcome most of the limitations associated with the possibility of obtaining this material. TPU scientists together with researchers from Jilin University and Qingdao University (China) have confirmed the high potential of using the material for electrocatalytic hydrogen production.
In the near future, scientists plan to learn how to control the characteristics of the material in order to further increase the catalytic activity of the material and completely abandon the use of expensive noble metals.
The research was carried out with the support of the Russian Science Foundation.