Berlin 2015 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 6: Catalysis
O 6.6: Vortrag
Montag, 16. März 2015, 12:00–12:15, MA 043
First-principles based modeling of the transport reactivity coupling: Catalytic explosion and non-chemical oscillations — •Sandra Döpking1,2, Karsten Reuter1,3, and Sebastian Matera1,2 — 1Technische Universität München, Germany — 2Freie Universität Berlin, Germany — 3Stanford University, USA
Bridging the gap between ultra-high vacuum and realistic operation conditions is the goal of in-situ studies of defined model catalysts. In these near ambient environments a further level of complexity arises by the coupling of surface chemical reactions with macro-scale heat and mass transport. To investigate such effects, we revisit the CO oxidation on the RuO2(110) in a stagnation flow reactor [1]. Differently to the previous studies, we now perform fully spatially and temporally resolved simulation employing our a first-principles based multi-scale modeling approach, which integrates kinetic Monte Carlo simulations into the Computational Fluid Dynamics code catalyticFOAM [2]. We find that, after changing the inlet composition, the surface experiences a rapid explosion-like heat up by several hundred Kelvin. Furthermore, depending on the diameter of the single crystal, the system may end up in an oscillating state. However, these oscillations are non-chemical, i. e. they originate from the thermo-convection driven by the temperature difference between inlet and surface. [1] S. Matera and K. Reuter, Catal. Lett. 133, 156 (2009); Phys. Rev. B 82, 085446 (2010); J. Catal. 295,261 (2012). [2] S. Matera, M. Maestri, A. Cuoci, and K. Reuter, ACS Catal. 4, 4081 (2014).