In many industries, including the automobile industry, catalysts are crucial for increasing product yield and protecting the environment. In particular, catalysts in car emission control systems are repeatedly exposed to temperature extremes. If the catalyst is unstable under such temperature changes, the catalyst is impractical for use in industrial processes. Therefore, industrial demands for catalysts that are both highly active and stable in temperature changes are high. Recently, a research team of Professor Han Jeong Woo of the Department of Chemical Engineering (CE), Kim Hyung Jun (CE Ph.D. Candidate), Shin Dongjae (CE Ph.D. Candidate), and KAIST researchers led by Prof. Hyunjoo Lee (KAIST) designed a stable and highly active ceria catalyst (CeO2) doped with lanthanum and copper. The study was published in the Dec. 18, 2020 issue of the international journal, ACS Catalysis, and was presented on the cover page.
The research team combined computational chemistry and experimental research. The team first hypothesized that the experimentally synthesized ceria catalyst would be highly stable and ultra-active using computational chemistry. To test this hypothesis, the team then developed a ceria catalyst doped with rare earth metals and transition metals. This new catalyst oxidized carbon monoxide at a temperature about 150˚C lower compared to previous ceria catalysts. Furthermore, it showed better catalyst activity than any previous catalysts placed under large temperature fluctuations.
Doping with rare earth metals stabilized the catalyst by inhibiting sintering (making a powdered material coalesce by heating) that could lead to catalyst deactivation. Doping with transition metals increased the catalyst activity by facilitating the formation of surface defects.
Prof. Han called the research “an exemplary case in which the theoretical team and experimental team verified the theoretical hypothesis under a mutually complementary and systematic research system,” and added, “such catalyst design methods could design ultra-stable, highly active oxide materials for a variety of catalytic reactions.”
The research was supported by the Basic Science Research Program of the National Research Foundation of Korea and the National Supercomputing Center of the Korea Institute of Science and Technology Information.