Dresden 2011 – scientific programme
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O: Fachverband Oberflächenphysik
O 97: Heterogeneous catalysis II
O 97.4: Talk
Friday, March 18, 2011, 12:00–12:15, PHY C213
Exploring Morphology-Activity Relationships: Ab Initio Thermodynamics Wulff Construction of RuO2 — •Jelena Jelic1,2 and Karsten Reuter1,2 — 1Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin — 2Technische Universität München
Systematic studies on polycrystalline powders are an appealing link between detailed Surface Science work on single crystals and the supported nanoparticles in real catalysis. On the other hand, the catalytic activity of the powder is sensitively influenced by the preparation procedure, with structure-morphology-activity relationships still only scarcely understood and controlled. A prominent example in this respect are the recently reported, largely different induction times for the CO oxidation over RuO2 powder [1,2]. Suspecting differing calcination temperatures behind these findings we use ab initio thermodynamics for a Wulff construction of RuO2 crystallites in contact with an oxygen gas-phase. Depending on the calcination temperature we indeed obtain distinctly different equilibrium shapes. Correlating the exposed facets with the reported activity data points to a prominent role of the hitherto not much studied (101) and (111) facets. [1] V. Narkhede, J. Assmann, and M. Muhler, Z. Phys. Chem. 219, 979 (2005); [2] D. Rosenthal et al., Z. Phys. Chem. 223, 183 (2009).