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O: Fachverband Oberflächenphysik
O 31: Heterogeneous Catalysis: Theory
O 31.2: Vortrag
Dienstag, 8. März 2016, 10:45–11:00, S053
NO-induced inhibition of oxide formation on Pd catalysts: A first-principles kinetic Monte Carlo study — •Juan Manuel Lorenzi1, Sebastian Matera2, and Karsten Reuter1 — 1Technische Universität München, Germany — 2Freie Universität Berlin, Germany
In the context of NOx Storage Reduction (NSR) catalysts, in which oxidation of NO into NO2 is a critical intermediate step, interest shifts to understanding the oxidation properties of typically employed Pt-group catalysts under the simultaneous exposure to CO, NO and O2. We assess this for a model Pd(100) catalyst by means of a comprehensive first-principles kinetic Monte Carlo study, which is based on an extensive set of density-functional theory derived rate constants and which explicitly resolves lateral interactions among all surface species. Multiple studies on Pd(100) in a pure CO + O2 atmosphere had indicated a strong propensity to surface oxide formation under technologically relevant gas-phase conditions (e.g. [1]). In contrast to this we find that already small amounts of NO in the feed lead to a substantial reduction of the O coverage even in oxygen-rich environments. While NO thus efficiently inhibits oxide formation, the total activity of the resulting metal surface towards NO (and CO) oxidation is still comparable to the one predicted previously for the oxidized surface [2]. [1] S. Blomberg et al., Phys. Rev. Lett. 110, 117601, (2013). [2] J. Jelic, K. Reuter, and R. Meyer, Chem. Cat. Chem. 2, 658 (2010).