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O: Fachverband Oberflächenphysik

O 99: Gerhard Ertl Young Investigator Award: Finalists session

O 99.4: Vortrag

Donnerstag, 4. März 2021, 15:00–15:30, R1

Probing surface electronic structure and reaction intermediates in situ — •Kelsey Stoerzinger — Oregon State University, Corvallis, Oregon USA — Pacific Northwest National Laboratory, Richland, Washington USA

Catalysts are important constituents in numerous energy conversion and storage processes. Rational design of catalysts with greater activity for higher efficiency devices requires an understanding of the material surface's electronic structure in situ, as well as the reaction intermediates involved.

Many surface science techniques, such as X-ray photoelectron spectroscopy (XPS), collect information from inherently surface-sensitive low-energy processes, requiring operation in ultrahigh vacuum. This constraint is lifted for ambient pressure XPS, which can probe the surface in equilibrium with the gas phase at pressures up to ~a few Torr, or with thin liquid layers using a higher incident photon energy. I will discuss the insights obtained with this technique regarding the electronic structure of well-defined epitaxial oxides in equilibrium with a gaseous atmosphere of small molecules (e.g. O2, H2O, CO2, CH3OH, NO), the adsorption of such species, and their subsequent transformation upon driving a desired reaction by heat, voltage, or additional reactant. Adsorption and reactivity can be manipulated by the oxide composition and electronic structure, crystallographic orientation, strain, and local environment in amorphous materials. This molecular-level understanding of interfacial interactions can guide the rational design of high-surface-area oxide catalysts for technical applications.