Berlin 2018 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 34: Focus Session: Frontiers of Electronic-Structure Theory: Correlated Electron Materials VII (joint session O/TT/MM/DS/CPP)
DS 34.10: Vortrag
Donnerstag, 15. März 2018, 17:30–17:45, HL 001
From DFT to Coupled Cluster Theory - Understanding Oxygen Activation on Coin Metal Nanoparticles — •Wilke Dononelli and Thorsten Klüner — Institut für Chemie, Carl von Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany
In this study we focus on one of the most fundamental catalytic model reactions, the oxidation of CO on a metal catalyst. We studied the activation of molecular oxygen via dissociation or direct reaction of CO and O2 within density functional theory (DFT) and high level CCSD(T) calculations. Therefore we use Au13 and Au55 nanoparticles (NPs) and a periodic Au(321) surface as model systems and compare the catalytic activity of the gold substrates to Ag and Cu based, as well as bimetallic NP catalysts. Part of the DFT calculations were performed, using the well-established PBE functional as implemented in the Vienna ab initio simulation package (VASP). Hybrid and double hybrid DFT calculations on the NPs were performed in Gaussian09. CCSD(T) calculation were performed in Gaussian09 using conventional CCSD(T) for the M13 (M=Au,Ag,Cu) NPs and CCSD(T)/PBE in a QM/QM embedding scheme using the ONIOM approach for M55 NPs. For systems of 55 metal atoms PBE gives the same results as double hybrids or even CCSD(T). For smaller M13 NPs interaction energies differ between PBE and higher levels of theory, which might be explained by the molecule like character of these NPs.