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O: Fachverband Oberflächenphysik

O 49: Oxide and Insulator Interfaces I

O 49.5: Vortrag

Mittwoch, 20. März 2024, 11:30–11:45, MA 144

Bridging the Pressure and Materials Gap in Heterogeneous Catalysis: A Combined UHV, In Situ, and Operando Study Using Infrared Spectroscopy — •Lachlan Caulfield, Eric Sauter, and Christof Wöll — Karlsruher Institut für Technologie (KIT)/Campus Nord, Hermann-von-Helmholtz-Platz 1,Eggenstein-Leopoldshafen, 76433,Germany

In the last decades, ceria-based systems have seen an increase in popularity, due to its unique redox behavior and catalytic characteristics. Ceria powders are widely used in exhaust catalysts as three-way catalysts (TWC) well as many other catalytic cycles, due to the cheap and simple preparation methods. To gain a better understanding of the chemical and structural behavior of ceria nanoparticles and their interaction with gaseous molecules, an operando DRIFTs study was carried out in combination with in-situ FT-IR studies. By tuning the temperature of the sample under a constant flow of carbon monoxide the reactions on the surface could be monitored in real time, without changing the surface. Notably, increasing the temperature from liquid nitrogen temperature to room temperature and above, it is possible to observe very minor changes to the oxidation state of the ceria nanoparticles as the surface becomes increasingly reduced. Using operando DRIFTS in combination with carbon monoxide dually as a reducing agent and as a probe molecule, the chemical and structural changes of polycrystalline ceria and other metal oxides can easily be investigated.

Keywords: Operando; DRIFTS; Ceria; Carbon monoxide; CO-SLIR