Berlin 2018 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 16: Heterogeneous Catalysis: Theory

O 16.1: Vortrag

Montag, 12. März 2018, 15:00–15:15, MA 141

The devil is in the defects: first-principles modeling of oxide formation at Pd(100) — •Albert Bruix and Karsten Reuter — Technical University Munich

The surfaces of many late transition metals are oxidized under ambient conditions or at increased oxygen pressures, which has strong implications for corrosion and catalysis. Stable O-enriched states resulting from oxidation may consist of the metal surface with high concentration of adsorbed O atoms, the corresponding metal-oxide, or something in between (e.g. surface oxides). A quantitative atomistic modeling of oxidation reactions catalyzed on transition metals therefore requires an understanding of the properties and formation mechanisms of the oxidized surfaces. In this work, the oxidation of Pd(100) to the corresponding surface oxide phase PdO(101)/Pd(100) formed on it is addressed by means of Density Functional Theory calculations. We focus on the oxidation mechanisms involving the pristine metal surface and different surface defects. The under-coordinated sites at surface steps, kinks, and small clusters or islands are found to play an important role in the oxidation process, affecting both the initial adsorption of oxygen and the transformation to the surface oxide phase.