Dresden 2017 – scientific programme
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O: Fachverband Oberflächenphysik
O 93: Heterogeneous Catalysis: Experiment
O 93.4: Talk
Thursday, March 23, 2017, 16:15–16:30, TRE Phy
Reactivity of quasi one-dimensional CoO2 nanostructures on Ir(100) — Pascal Ferstl1, M. Alif Arman2, Jan Knudsen2, Edvin Lundgren2, Lutz Hammer1, and •M. Alexander Schneider1 — 1Lst. f. Festkörperphysik, FAU Erlangen-Nürnberg, Germany — 2Division of Synchrotron Radiation Research, Lund University, Sweden
In this study we analyze the catalytic properties of quasi one-dimensional CoO2 nanostructures grown on the Ir(100) surface [1], exemplified by the oxidation of hydrogen and CO. Due to the long range order of the system before and after the reactions it was possible to quantify the structural changes by means of full dynamical LEED analyses. Combining this detailed structural information with data obtained by HR-XPS, STM and TDS we were able to follow the processes during the reactions in situ on the atomic scale.
We thus identified the relevant species during the different stages of the two oxidation reactions. Further the observed structural changes hint at the importance of defects like grain boundaries for the reaction kinetics. In summary, the cobalt oxide nanostructures enable both reactions at temperatures lowered by 150 K − 200 K compared to the oxygen covered Ir(100)-(2×1)O surface [2] and therefore show high catalytic activity.
[1] P. Ferstl, et al., Phys. Rev. Lett. 117, 046101 (2016); [2] P. Ferstl, et al., Phys. Rev. B 93, 235406 (2016)