A KAIST and Stanford University joint research team revealed research results that overturn long-standing beliefs in the field of nanomaterials. Contrary to the conventional perception that mixing more metals complicates the system, this study revealed for the first time that complex compositions actually create more uniform nanoparticles (extremely small particles, about 1/100,000th the thickness of a human hair), signaling a new turning point for next-generation energy and catalysis technology.
KAIST (President Kwang Hyung Lee) announced that a joint research team led by distinguished professor Hee-Tae Jung from the Department of Chemical and Biomolecular Engineering and Professor Matteo Cargnello from Stanford University has identified a "paradoxical phenomenon" where mixing more metals leads to the formation of more uniform nanoparticles.
Nanoparticles are core materials in various industries such as semiconductors, eco-friendly energy, and biotechnology. Recently, they have evolved into "multimetallic" structures to improve performance. However, as the number of constituent elements increases, the different reaction rates of each element cause variations in particle size and shape, which has been considered a major challenge for precision control.
The research team focused on "composition-focusing," a phenomenon where the particle components converge in one direction and become more uniform as the number of metal elements increases.
The research confirmed that during the competitive bonding process of different metal atoms, the atoms that settle first act as a "stepping stone," helping subsequent atoms attach more easily. Consequently, instead of mixing randomly, the atoms stack orderly in layers to form a stable structure. This phenomenon is a significant discovery, showing that the complex chemical reaction environment – previously viewed as a hurdle – actually helps atoms achieve an organized structure.
To verify this principle, the team produced a multimetallic nanoparticle catalyst containing five different metals. In the reaction of decomposing ammonia to produce hydrogen – which requires high temperatures and high-performance catalysts – the new material showed four-times higher efficiency than the ruthenium catalyst, the current industrial standard.
Distinguished professor Hee-Tae Jung stated: "This research is significant in that it discovered an unexpected 'paradoxical phenomenon' and identified its operating principle. By utilizing this principle, we can design metal compositions tailored to desired performance, which is expected to be used in developing high-performance catalysts and eco-friendly energy materials for processes like hydrogen production and carbon dioxide conversion.
Jeesoo Yoon, a PhD candidate at KAIST, and Dr. Jinwon Oh from Stanford University participated as co-first authors of this study. The research was led by Distinguished Professor Hee-Tae Jung of KAIST and Professor Matteo Cargnello of Stanford University as co-corresponding authors. BASF (Badische Anilin- & Soda-Fabrik) and Seoul National University also participated in the joint research. The findings were published in the world-renowned academic journal Science on May 7th.
※ Title: Competitive reactivity drives size- and composition-focusing in multimetallic nanocrystals
※ DOI: 10.1126/science.aea8044
This research was conducted with the support from the National Research Foundation, the Korea Institute of Energy Technology Evaluation and Planning, and BASF. (End)
