Regensburg 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 43: Oxides and Insulators: Adsorption II
O 43.2: Vortrag
Mittwoch, 28. März 2007, 16:00–16:15, H42
Influence of Electronic Correlations on the Ground-State Properties of Cerium Dioxide Bulk and Surfaces — •Elena Voloshina1, Carsten Mueller2, Beate Paulus1, and Kersti Hermansson2 — 1MPI fuer Physik komplexer Systeme, Noethnitzer Str. 38, 01187 Dresden, Germany — 2Department of Materials Chemistry, The Angstroem Laboratory, University of Uppsala, Box 538, Laegerhyddsvaegen 1, 75121 Uppsala, Schweden
Ceria plays an important role as a component in the active noble metal support in automotive three-way catalytic converters, where NOx, CO, and hydrocarbons are simultaneously removed [1]. The electron-correlation effects on the ground-state properties of bulk CeO2 are studied by ab initio quantum-chemical methods. For this purpose the method of increments is applied. It combines Hartree-Fock calculations for periodic systems with correlation calculations requiring only information of the corresponding finite-cluster calculations. After inclusion of correlations obtained at the CCSD(T) level the calculated values are in good agreement with experiment [2]. With this detailed description of the electronic correlations in bulk CeO2, it is now possible to extend the work to CeO2 surfaces and adsorbed molecules on them. Here we present absorbtion energies of CO and N2O. Especially for these weakly bound molecules an explicitely correlated method is necessary to describe accurately the van der Waals interaction.
[1] J. Kaspar, P. Fornasiero, and M. Graziani, Catal. Today 50, 285 (1999).
[2] E. Voloshina and B. Paulus, J. Chem. Phys. 124, 234711 (2006).