Dresden 2003 – wissenschaftliches Programm
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O: Oberflächenphysik
O 7: Hauptvortrag Neyman
O 7.1: Hauptvortrag
Montag, 24. März 2003, 14:00–14:45, HSZ/02
Quantum Chemistry of d-Metal Species Deposited on Oxides: From Atoms to Nanoparticles — •Konstantin M. Neyman — Institut für Physikalische und Theoretische Chemie, Technische Universität München, 85747 Garching
Density functional model cluster studies of supported transition and noblemetal species on surfaces of non-reducible ionic metal oxides (MgO, Al2O3) and in zeolites will be overviewed. Computational approaches and design of realistic embedded cluster models of oxide supports will be discussed. Characteristic features of the initial stage of metal/oxide interface formation will be considered in the light of quantum chemical results obtained for small metal species M1-M5 (M = Cr, Mo, W; Ni, Pd, Pt; Cu, Ag, Au; Re, Os, Ir, Rh) adsorbed at ideal surface sites and defects of the oxide supports.
Among others, the following questions will be addressed: (i) preferred sites for metal deposition on regular surfaces and defects; (ii) electronic and geometric structure of supported metal particles; (iii) strength of metal-support interactions in comparison with metal-metal interactions; (iv) nature of bonds between metal particle and oxide support; (v) charge distribution between deposit and support.
Results of all-electron calculations on significantly larger symmetric palladium clusters of about 100 atoms as models of supported catalysts built of well-characterised metal nanoparticles will also be presented. Conceivable ways of improving accuracy of high-level computational studies of complex systems will be traced.