Regensburg 2022 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 52: Poster Wednesday: Adsorption and Catalysis 2
O 52.8: Poster
Mittwoch, 7. September 2022, 18:00–20:00, P4
CO→CO2 conversion over Pt/SiO2/Si model catalyst — •Artur Böttcher1, Pascal Weisenburger1, David Rettinger1, Jakob Hauns1, Rahul Parmer2, Matteo Amati2, Luca Gregoratti2, and Manfred Kappes1 — 1Institute of Physical Chemistry, KIT, 76131 Karlsruhe, Germany — 2Elettra - Sincrotrone Trieste ScPA, Area Science Park, 34149 Basovizza-Trieste, Italy
We studied the thermal stability of the Pt/SiO2/Si interface as the model catalyst for CO oxidation reaction. The 2D catalysts were prepared under UHV conditions by growing very thin Pt films on the SiO2/Si wafer and subsequently performing a long-term annealing of the interface at elevated temperatures, T*(700-900K). Such a treatment results in the formation of the submicron-sized islands. The size/shape distribution of the islands scales primarily with the thickness of the Pt film. The chemical state of the islands as probed by ESCA microscopy (Elettra) evidences the formation of PtSinOm alloys as the dominating component of the islands. The CO2 light-off curves taken for Pt/SiO2/Si interfaces fabricated at room temperature reveal the highest CO/CO2 conversion yield, Y, and the lowest activation temperature, TA∼400 K. Increasing alloying degree considerably quenches the conversion yield and shifts up the CO/CO2 conversion onset.