Hydrogen fuel cell performance can be drastically improved according to a team of scientists from Korea who have developed metal nanoparticles using a physical method rather than the existing chemical reactions by using the sputtering technology, which is a thin metal film deposition technology used in semiconductor manufacturing.
Metal nanoparticles aren’t new and they have been point of study for quite a few years now and in multiple science streams. The research into nanoparticles has also attracted attention of fuel cell researchers and they have found themselves as a research point from a point of view of being a critical catalyst for hydrogen fuel cells and water electrolysis systems to produce hydrogen.
Complex chemical reactions are how metal nanoparticles are mainly prepared, but not only these chemical reactions are costly they are also harmful to environment and humans. Scientists have been looking for a new nanoparticle synthesis method that can overcome the shortcomings of the existing chemical synthesis is required to establish the hydrogen energy regime.
That’s where the latest research by KIST research team comes to the fore. The sputtering process coats a thin metal film during the semiconductor manufacturing process. In this process, plasma is used to cut large metals into nanoparticles, which are then deposited on a substrate to form a thin film. The research team prepared nanoparticles using ‘glucose’, a special substrate that prevented the transformation of the metal nanoparticles to a thin film by using plasma during the process. The synthesis method used the principle of physical vapor deposition using plasma rather than chemical reactions. Therefore, metal nanoparticles could be synthesized using this simple method, overcoming the limitations of the existing chemical synthesis methods.
The development of new catalysts has been hindered because the existing chemical synthesis methods limited the types of metals that could be used as nanoparticles. In addition, the synthesis conditions must be changed depending on the type of metal. However, it has become possible to synthesize nanoparticles of more diverse metals through the developed synthesis method. In addition, if this technology is simultaneously applied to two or more metals, alloy nanoparticles of various compositions can be synthesized. This would lead to the development of high-performance nanoparticle catalysts based on alloys of various compositions.
The KIST research team synthesized a platinum-cobalt-vanadium alloy nanoparticle catalyst using this technology and applied for the oxygen reduction reaction in hydrogen fuel cell electrodes. As a result, the catalyst activity was 7 and 3 times higher than those of platinum and platinum-cobalt alloy catalysts that are commercially used as catalysts for hydrogen fuel cells, respectively. Furthermore, the researchers investigated the effect of the newly added vanadium on other metals in the nanoparticles. They found that vanadium improved the catalyst performance by optimizing the platinum–oxygen bonding energy through computer simulation.