Researchers have developed an advanced platinum nanocatalyst that significantly improves hydrogen production efficiency. This breakthrough hybrid catalyst has higher activity and stability and is expected to be used in hydrogen-powered vehicles. Data from South Korea’s Ministry of Land, Infrastructure, Transport and Tourism show that by 2022, there will be approximately 30,000 hydrogen-powered vehicles registered in South Korea, a threefold increase from 2018. However, South Korea only has 135 hydrogen refueling stations.
For hydrogen to become more readily available for use in vehicles and to be recognized as a reliable alternative energy source, hydrogen production costs must be reduced and its economic viability must be ensured. Central to this goal is optimizing the efficiency of the electrolysis-hydrogen evolution process, which produces hydrogen gas from water.
Recently, a research team composed of Professor InSuLee, Research Professor SoumenDutta, and ByeongSuGu from the Department of Chemistry at Pohang University of Science and Technology (POSTECH) significantly improved the production efficiency of hydrogen, a green energy, by developing platinum nanocatalysts.
They accomplished this by gradually depositing two different metals. Their findings were published in Angewandte Chemie, a highly respected journal dedicated to the field of chemistry.
Selectively depositing different materials, whose dimensions are in the nanometer range, at specific locations on the catalyst surface poses significant challenges. Accidental deposition may block the catalyst's active sites or interfere with each other's function. This dilemma prevents the simultaneous deposition of nickel and palladium on a single material. Nickel is responsible for activating the splitting of water, while palladium facilitates the conversion of hydrogen ions into hydrogen molecules.
The research team developed a new type of nanoreactor that can finely control the position of metal deposited on two-dimensional planar nanocrystals. In addition, they also designed a nanoscale fine deposition process that allows different materials to cover different sides of the two-dimensional platinum nanocrystals. This new method developed a "platinum-nickel-palladium" three-metal hybrid catalyst material. Through continuous deposition, palladium and nickel nanofilms selectively cover the planes and edges of two-dimensional platinum nanocrystals, respectively.
The hybrid catalyst has unique nickel/platinum and palladium/platinum interfaces, which are used to promote water separation and hydrogen molecular generation processes, respectively. Therefore, the synergy of these two different processes greatly improves the efficiency of electrolysis-hydrogen evolution.
Research results show that compared with traditional platinum carbon catalysts, the catalytic activity of the three-metal hybrid nanocatalyst is increased by 7.9 times. In addition, this new catalyst has remarkable stability and maintains high catalytic activity even after reaction times of up to 50 hours. This solves the problem of functional interference or collision between heterogeneous interfaces.
Professor InSuLee, who led the research, expressed optimism: "We successfully developed a harmonious heterogeneous interface formed on hybrid materials and overcame process challenges. I hope that the research results can be widely used in the development of hydrogen reaction catalytic materials."