Berlin 2015 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 6: Catalysis
O 6.8: Vortrag
Montag, 16. März 2015, 12:30–12:45, MA 043
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
The CO oxidation reaction on two types of TiO2 nanotube-supported Pt particle samples was examined by near-ambient pressure (NAP)-XPS and simultaneous online gas analyses. Both samples consist of vertical nanotubes (d=80, l=100 nm) decorated with platinum particles of different size. Temperature-programmed reaction experiments in continuous flow mode at a total pressure of 1 mbar and a CO:O2 ratio of 1:4 were performed in the temperature range of 300 to 600 K. We compare these experiments to results obtained for the CO oxidation on a Pt(111) single crystal. The reaction onset temperatures were obtained by online gas analyses while the surface chemistry was investigated by XPS: we find a lower onset temperature on the nanoparticles with decreasing size and overall compared to Pt(111). Isothermal reactions were performed in-situ before at and above the onset temperatures, showing no adsorbed CO after reaction onset. Strong ageing of the samples with reaction time was observed resulting in changes of the reaction onset and CO conversion.