AVS 51st International Symposium
    Surface Science Monday Sessions
       Session SS1-MoA

Paper SS1-MoA7
Ab Initio Molecular Dynamics Study of Methanol Adsorption and Reaction on Copper Clusters

Monday, November 15, 2004, 4:00 pm, Room 210B

Session: Simulation and Theory of Adsorption
Presenter: W.-D. Hsu, University of Florida
Authors: W.-D. Hsu, University of Florida
S.B. Sinnott, University of Florida
Correspondent: Click to Email
The reaction of methanol molecules with size-selected Cu@sub n@ clusters, n=2-9, is investigated by first-principles molecular dynamics simulations. The simulations use density functional theory within the generalized gradient approximation and ultrasoft pseudopotentials. The molecules are deposited on the Cu clusters with an incident energy of 0.5 eV/molecule. The structure, dynamics, and reaction energy are studied as a function of the cluster size. Experiments by Kondow and co-workers@footnote 1@ find that the dominant reactions are methanol chemisorption, demethanation, and carbide formation, which are very different from the interaction of methanol with bare copper surfaces, where physisorption is the dominant outcome. The simulations detail the atomic scale mechanisms that are responsible for these differing behaviors. For example, they show that the adsorption energy of methanol to Cu@sub 7@ is about 0.5 eV, which is larger than the energy of adsorption of methanol on the Cu(111) surface@footnote 2@@super ,@@footnote 3@ by about 0.25 eV. The simulations also illustrate the differences in the interaction of methanol with copper clusters of various sizes. This work is supported by the National Science Foundation (CHE-0200838). @FootnoteText@ @footnote 1@M. Ichihashi, T. Hanmura, R. T. Yadav, and T. Kondow, J. Phys. Chem. A 104 (2000) 11885@footnote 2@J. R. B. Gomes, and J. A. N. F. Gomes, Surf. Sci. 471 (2001) 59@footnote 3@J. Greeley, and M. Marvrikakis, J. Cataly. 208 (2002) 291.