Characterization of H and CO adsorption on Cu(110) surfaces with and without defects

BATISTA, M.N.; MARTÍNEZ, A.E.

Bordeaux

Workshop; Elementary Reactive Processes at Surfaces - 3rd edition; 2010

Universite Bordeaux I

p { margin-bottom: 0.21cm; } The aim of the present work is to characterize the changes in the reactivity of a given surface due to the presence of defects. We study two different systems, H/Cu(110) and CO/Cu(110), and for each one we consider the cases of the surface with or without defects. Electronic structure calculations based on density functional theory (DFT/GGA) are performed within the slab/supercell approach, to determine the interaction of H and CO with the Cu surfaces. We carry out a comparative study of the reactivity towards hydrogen of a Cu(110) surface, starting from the perfect surface and introducing different kind of defects (as vacancies, adatoms, steps and kinks). We determine the differences in the adsorption energies and the most favourable adsorption sites by comparison of the H/Cu(110) potential for different sites on the defect-free Cu(110) surface and the analogous ones for each surface with defects considered. On the other hand, we study the molecular adsorption of CO on Cu(110). This system has been already characterized from the experimental side for a perfect surface and for a surface where defects were induced by sputtering. The latter is represented in our theoretical modelization by a surface with vacancies. The global energetics of the adsorption process for the CO/Cu(110) surfaces are analyzed by inspection of 2D (Z,r) cuts of the potential energy surfaces (PES). The most favourable adsorption sites and structural parameters are also determine. A continuos representation of the 6D PES for both surfaces is obtained by using the Corrugation Reducing Procedure (CRP) in order to carry out classical trajectories dynamical calculations.