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Platinum selenaide is a two-dimensional material formed by the layered combination of platinum (Pt) and selenium (Se). Its excellent crystallinity and precise control of interlayer interactions allow for the modulation of various physical and chemical properties. It has been actively researched in various fields, such as semiconductors, photodetectors, and electrochemical devices.

Now a research team has proposed a new design concept where atomic-level platinum present on the surface of platinum selenaide can function as a catalyst for gas reactions. Through this, they have proven its potential as a next-generation gas-phase catalyst technology for high-efficiency carbon dioxide conversion and carbon monoxide reduction.

A joint research team led by Endowed Chair Professor Jeong Young Park from the Department of Chemistry, along with Professor Hyun You Kim's team from Chungnam National University and Professor Yeonwoong Jung's team from the University of Central Florida (UCF), has succeeded in achieving excellent carbon monoxide oxidation performance by utilizing platinum atoms exposed on the surface of the two-dimensional transition metal dichalcogenide, platinum diselenide (PtSeâ‚‚). Their findings are in Nature Communications.

To maximize catalytic performance, the research team designed the catalyst so that platinum atoms are highly dispersed on the surface, moving away from conventional bulk platinum catalyst forms. This approach enables more catalytic reactions with a smaller amount of platinum and promotes active electronic interaction between the platinum and selenium by controlling the surface's electronic structure.

The platinum diselenide thin film, several nanometers thick, showed superior carbon monoxide oxidation performance across the entire temperature range compared to a general platinum thin film under the same conditions.

In particular, on the surface, carbon monoxide and oxygen were adsorbed evenly in similar proportions, increasing the opportunity for them to react with each other, which significantly enhanced the catalytic reaction. The key to this performance enhancement lies in the increased exposure of surface platinum atoms due to "selenium vacancies (Se-vacancy)," which also increased the adsorption sites for gases.

The research team confirmed in real time that these platinum atoms acted as adsorption sites during the actual reaction process through 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 a 1-nanometer level in an ambient pressure environment. Simultaneously, computer simulation (Density Functional Theory) calculations theoretically proved that platinum diselenide has different electron flow characteristics than general platinum.

Professor Jeong Young Park stated, "This research presents a new design strategy that utilizes platinum diselenide, a two-dimensional layered structure different from conventional platinum catalysts, to elicit catalytic functions specialized for gas reactions.

"The electronic interaction between platinum and selenium created reaction conditions for the balanced adsorption of carbon monoxide and oxygen, and by designing it to have higher reactivity across the entire temperature range than conventional platinum, its practical applicability has been improved. This allowed us to achieve a high-efficiency catalytic reaction mechanism through atomic-level design, a two-dimensional material platform, and adsorption control technology."

This research was co-authored by Dr. Gyuho Han from KAIST's Department of Chemistry, Dr. Hyuk Choi from Chungnam National University's Department of Materials Science and Engineering, and Professor Jong Hun Kim from Inha University.