Chemistry Department Seminar

Metal deposition constitutes one of the most appealing methods for the preparation of new materials of technological interest (catalysis, gas sensors, electronic devices,…). Addition of metal atoms to a surface can in principle look for different targets. Thus, a given relatively inert surface can be promoted by adding an alkali metal like Na. In another direction, specific catalysts are prepared by supporting transition metal atoms on inert surfaces. In these materials several questions are relevant from a microscopic point of view. First we are interested by the properties of the metal surface interface: the nature of the bond, the extension of the surface reduction, etc. Secondly, we would like to know the detailed structure of the particles adsorbed at the surface. This information could help for both a better understanding of the interface and a suitable description of the active sites in a given surface reaction. In this contribution we report on a theoretical work aimed to analyze these two aspects in catalytically relevant metal-support systems. Preferred sites and the nature of the metal-surface interaction has been analyzed by means of density functional based calculations under the GGA approach, using a periodic slab model of different thickness. The growth mechanism of Cu clusters on the surface at the early stages of deposition has been examined through BO molecular dynamics simulations.
Some references:
N. Cruz Hernández y J. Fdez. Sanz Molecular Dynamics Simulations of Pd Deposition on the α-Al2O3 (0001) Surface.
J. Phys. Chem. B 2001, 105, 12111-12117.
N. Cruz Hernández y J. Fdez. Sanz A first principles study of Cu atoms deposited on the α-Al2O3(0001) surface.
J. Phys. Chem. B 2002, 106, 11495-11500.
N. Cruz Hernández, Jesús Graciani, A. Márquez y Javier Fdez. Sanz Cu, Ag and Au atoms deposited on the α-Al2O3(0001) surface: a comparative density functional study Surf. Sci. 2005, 575, 189-196
J. F. Sanz y N. Cruz He