Regensburg 2016 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 73: Surface Dynamics: Reactions and Elementary Processes
O 73.2: Poster
Mittwoch, 9. März 2016, 18:15–20:30, Poster A
CO oxidation on TiO2 nanotube-supported Pt particles at near ambient pressures — •Sandra Krick Calderon1, Mathias Grabau1, Jeong Eun Yoo2, Patrik Schmuki2, Hans-Peter Steinrück1, and Christian Papp1 — 1Physikalische Chemie II, University of Erlangen-Nürnberg, Egerlandstr. 3 — 2Lehrstuhl für Korrosion und Oberflächentechnik, University of Erlangen-Nürnberg, Martensstraße 7, 91058 Erlangen, Germany
We investigated the oxidation of CO on different platinum model catalysts, i.e., differently sized Pt particles on vertical TiO2 nanotubes (d=80, l=100 nm); the results are compared to the behaviour on a TiO2(110) rutile crystal with a similar Pt content and a Pt(111) single crystal. Temperature-programmed reaction experiments at total pressures of 1.0 and 0.1 mbar, and a CO:O2 ratio of 1:4 and 2:1, were examined by near-ambient pressure XPS in the temperature range from 300 to 800 K. Additionally, we performed online gas analysis. The onset temperature of the reaction on the Pt/TiO2 nanotube samples was found to be lower than on Pt(111) and Pt/TiO2(110) and to decrease with decreasing particle size. After reaction onset no adsorbed CO was found on the particles and metallic platinum was the active catalyst. Strong ageing of the TiO2-supported samples with reaction time was observed resulting in changes of the reaction onset and CO conversion. Further measurements to elucidate the role of UV light for the enhancement of the reactivity will be discussed. The work was supported by Cluster of Excellence "EAM" of the Friedrich-Alexander-Universität.