A research team in Korea has synthesized metal nanoparticles that can significantly improve the performance of hydrogen fuel cell catalysts by using the semiconductor manufacturing technology. The Korea Institute of Science and Technology (KIST) announced that the research team led by Dr. Sung Jong Yoo of the Hydrogen Fuel Cell Research Center succeeded in synthesizing nanoparticles by a physical method rather than the existing chemical reactions by using sputtering technology—a thin metal film deposition technology used in semiconductor manufacturing.
The KIST research team synthesized a platinum-cobalt-vanadium alloy nanoparticle catalyst using this technology and applied it for the oxygen reduction reaction in hydrogen fuel cell electrodes. The resulting 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.
A paper on the work is published in the journal Nano Today.
Synthesis process for the preparation of ternary nanoparticle catalysts and electron structure rearrangement by electron transfer between metal atoms. Credit:
Korea Institute of Science and Technology (KIST)
Metal nanoparticles have been studied in various fields over the past few decades. Recently, metal nanoparticles have been attracting attention as a critical catalyst for hydrogen fuel cells and water electrolysis systems to produce hydrogen.
Metal nanoparticles are mainly prepared through complex chemical reactions. In addition, they are prepared using organic substances harmful to the environment and humans. Additional costs are inevitably incurred for their treatment, and the synthesis conditions are challenging. A new nanoparticle synthesis method that can overcome the shortcomings of the existing chemical synthesis is required to establish the hydrogen energy regime.
The sputtering process applied by the KIST research team is a technology that 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 a special glucose 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. 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 can lead to the development of high-performance nanoparticle catalysts based on alloys of various compositions.
This research was carried out as a major project of KIST, a technology development program to solve climate change, and a nanomaterial technology development program of the National Research Foundation of Korea with the support of the Ministry of Science and ICT.
Injoon Jang, Sehyun Lee, Eoyoon Lee, Dong-Wook Lee, Hee-Young Park, Baeck B. Choi, Hyung Chul Ham, Sung Jong Yoo (2021) “Plasma-induced alloying as a green technology for synthesizing ternary nanoparticles with an early transition metal,” Nano Today doi: 10.1016/j.nantod.2021.101316