South Korean Researchers Uncover New Catalyst Design Principle: Ceria's Oxygen Use Depends on Size
KAIST and Seoul National University teams reveal how ceria catalysts selectively utilize different oxygen sources based on their size and reaction environment, offering a new approach to combat greenhouse gases.
South Korean researchers have identified a new principle for catalyst design, revealing that ceria (CeOâ‚‚) catalysts selectively utilize different oxygen sources depending on their size and the reaction environment. This discovery addresses the critical global challenge of effectively removing greenhouse gases.
A joint research team, including Professor Hyunjoo Lee and Professor Jeong Young Park from KAIST, and Professor Jeong Woo Han from Seoul National University, announced on February 4th that they determined ceria, an eco-friendly catalyst, completely changes its oxygen usage method based on its size.
The Promise of Ceria Catalysts
Ceria is a metal oxide catalyst known for its ability to store and release oxygen, thereby reducing the reliance on expensive precious metal catalysts often used in industrial applications. Previously, the specific origin and conditions of oxygen utilization in ceria were not clearly identified.
Size Matters: Agility vs. Endurance
The research team developed catalysts with precisely controlled ceria sizes, from ultra-small nano-sizes to larger dimensions, to systematically analyze oxygen movement and reaction processes.
They confirmed a groundbreaking finding:
- Small ceria catalysts operate as an "agility type," quickly taking oxygen from the air for immediate reactions.
- In contrast, large ceria catalysts function as an "endurance type," continuously supplying internally stored oxygen to the surface.
This finding establishes that by simply adjusting the catalyst's size, one can choose between using atmospheric oxygen or internally stored oxygen based on specific reaction conditions.
This mechanism was thoroughly validated through both advanced experimental analysis and artificial intelligence-based simulations.
Application: Methane Removal
The practical implications of this discovery are significant, particularly in the realm of greenhouse gas removal. Methane, a greenhouse gas significantly more potent than carbon dioxide, was a key target.
Experiments showed that small ceria catalysts stably removed methane even in low-temperature and high-humidity environments by immediately utilizing oxygen from the air. This approach demonstrated improved performance while significantly reducing the need for expensive precious metals such such as platinum and palladium.
Future Impact and Custom Design
This achievement is expected to facilitate the development of highly durable catalysts that maintain performance in challenging industrial conditions, reduce manufacturing costs for environmental purification equipment, and accelerate the commercialization of eco-friendly energy and environmental technologies.
Professor Hyunjoo Lee stated that:
"This research clearly differentiates the two core mechanisms of oxygen operation in catalysts for the first time, paving a new path for custom-designing high-efficiency catalysts to address the climate crisis."
The study's joint first authors include Ph.D. candidate Yunji Choi and Ph.D. candidate Jaebeom Han from KAIST, and Dr. Seokhyun Choung from Seoul National University. The research was published in the international academic journal 'Nature Communications' on January 9th, supported by the National Research Foundation of Korea.