KAIST Proposes Novel Atomic Catalyst Design for Air Pollution Reduction

A new design concept has been proposed, suggesting that atomic-level platinum present on the surface of platinum selenide (PtSe₂) can function as a catalyst for gas-phase reactions. This concept is expected to be utilized as a next-generation gas-phase catalytic technology that could contribute to solving air pollution issues, such as carbon dioxide conversion and carbon monoxide reduction.

On July 22, KAIST announced that the research team led by Distinguished Professor Park Jungyoung from the Department of Chemistry, in collaboration with Professor Kim Hyunyu from Chungnam National University and Professor Jung Yeonwoong from the University of Central Florida (UCF), succeeded in demonstrating carbon monoxide oxidation performance using platinum atoms exposed on the surface of platinum selenide.

(From left) Professor Kim Jonghun, Dr. Han Kyuho, Professor Park Jungyoung. Provided by KAIST

Platinum selenide is a two-dimensional material in which platinum (Pt) and selenium (Se) are bonded in a layered structure. This material is known for its excellent crystallinity and the ability to precisely control interlayer interactions, allowing for the tuning of various physical and chemical properties.

The joint research team maximized the catalytic performance of platinum selenide by dispersing platinum atoms at high density on the surface, moving away from the conventional bulk platinum catalyst form. This approach enabled more catalytic reactions with a smaller amount of platinum.

In addition, by controlling the electronic structure of the surface to enhance electronic interactions between platinum and selenium, the team fabricated platinum selenide thin films just a few nanometers thick. As a result, under the same conditions, these films exhibited superior carbon monoxide oxidation performance compared to conventional platinum thin films.

This led to an increased likelihood of carbon monoxide and oxygen being adsorbed on the surface in similar proportions, thereby providing more opportunities for them to react with each other and significantly enhancing the catalytic reaction.

Schematic diagram of platinum selenide oxidation reaction. Provided by KAIST

The key to the improved performance lies in the 'selenium vacancy (Se-vacancy)'. As the exposure of surface platinum atoms increased due to these vacancies, the number of adsorption sites available for gas molecules also rose.

The joint research team confirmed in real time that platinum atoms acted as adsorption sites during the reaction process, using ambient pressure X-ray photoelectron spectroscopy (AP-XPS) analysis performed at the Pohang Accelerator Laboratory. This high-precision analysis was made possible by advanced equipment capable of observing surfaces at the one-nanometer scale under ambient pressure conditions.

At the same time, computer simulations (density functional theory calculations) theoretically demonstrated that platinum selenide possesses electronic flow characteristics distinct from those of conventional platinum. Density functional theory is a method for calculating the total energy of a system based on electron density.

Professor Park Jungyoung stated, "This research is significant in that it presents a new design strategy that draws out catalytic functions specialized for gas-phase reactions using the two-dimensional layered structure of platinum selenide, which is different from conventional platinum catalysts." He added, "The electronic interaction between platinum and selenium creates reaction conditions that allow carbon monoxide and oxygen to be adsorbed in a balanced manner, and the design enables higher reactivity at all temperatures compared to conventional platinum, increasing the potential for practical applications."

Meanwhile, Dr. Han Kyuho from the Department of Chemistry at KAIST, Dr. Choi Hyuk from the Department of Materials Science and Engineering at Chungnam National University, and Professor Kim Jonghun from Inha University participated as co-first authors. The research results (paper) were published in the July 3 issue of 'Nature Communications'.

This content was produced with the assistance of AI translation services.