Development of a Platform for Accurate Measurement of Metal Catalyst Performance

Published 28 Dec.2021 10:28(KST)

Joint Research Results by Professors Jung Woo-cheol and Lee Kang-taek of KAIST, and Professor Kim Hyun-yu of Chungnam National University

Figure 1. (a) Quantitative analysis platform composed of platinum nanoparticle-ceria catalyst, (b) metal-gas-oxide phase junction interface, and (c) three-dimensional image of the metal-gas phase junction interface. Scaling relationship results showing the number of (d) metal-gas-oxide phase and (e) metal-gas phase junction interfaces according to the size of metal nanoparticles.

[Asia Economy Reporter Kim Bong-su] KAIST announced on the 28th that Professors Jung Woo-cheol of the Department of Materials Science and Engineering and Lee Kang-taek of the Department of Mechanical Engineering, in collaboration with Professor Kim Hyun-yoo's research team at Chungnam National University, have succeeded in developing a metal nanoparticle-based analytical platform capable of locating catalytic reaction sites and quantitatively measuring the activity at each site.

A catalyst is a substance that accelerates the reaction rate without being consumed or changed during the reaction process. Since it participates in the reaction but is not consumed, even a small amount can continuously influence the reaction rate. Catalytic reactions that speed up reactions require less activation energy and are thus utilized in various industries. An example is the reaction that decomposes harmful byproducts of exhaust gases generated by the combustion of fossil fuels using platinum.

The research team quantitatively analyzed the number of metal-gas-oxide and metal-gas phase junction interfaces, which are key catalytic reaction sites, by utilizing uniform-sized metal nanoparticle synthesis technology and three-dimensional electron tomography techniques. They also designed a measurement platform that enables quantitative analysis of catalytic reaction activity by linking these results with measured catalytic reactivity. Since this technology is not limited to specific reactions, it is expected to be widely applied and utilized in various catalytic reaction fields in the future.

Metal nanoparticle catalysts have attracted great interest in fields such as energy and environment due to their potential to exhibit excellent catalytic activity with very small amounts.

However, catalysts composed of nanoparticles tend to agglomerate at high operating temperatures, which ultimately acts as a limitation that hinders catalytic activity. Moreover, there has been a lack of technology to quantitatively compare and analyze the exact reactive active sites of metal particle catalysts and their activity levels under actual reaction operating conditions, limiting progress in this field.

To address this issue, the research team succeeded in synthesizing metal nanoparticle catalysts with uniform sizes to control particle structure and applied a coating technology that encapsulates them with an oxide film to prevent nanoparticle agglomeration at high temperatures. By applying three-dimensional electron tomography, scaling relations, and density functional theory, and linking these with reactivity measured under various conditions, they identified specific reaction sites and their activities.

Although the study utilized platinum, a representative precious metal catalyst, and methane oxidation, a high-temperature catalytic reaction, the technology is expected to be broadly applicable across various fields regardless of material or reaction type.

Professor Jung Woo-cheol stated, "Through this research, we have established a highly reliable measurement platform that can quantitatively analyze the reaction characteristics of metal nanoparticle catalysts for given reactions," adding, "This is expected to be used in providing comprehensive catalytic design solutions, such as selecting excellent composite catalyst materials."