Dissociative adsorption of hydrogen on strained Cu surfaces

• Published in: Surface science 2003-02, Vol.525 (1), p.107-118
• Main Authors: Sakong, Sung, Groß, Axel
• Format: Article
• Language: English
• Subjects: Adsorption and desorption kinetics; evaporation and condensation; Chemisorption; Condensed matter: structure, mechanical and thermal properties; Copper; Density functional calculations; Exact sciences and technology; Hydrogen atom; Low index single crystal surfaces; Physics; Solid-fluid interfaces; Surface stress; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(02)02550-5

The adsorption and dissociation of hydrogen on strained clean and oxygen-covered Cu surfaces have been studied by calculations based on density functional theory within the generalized gradient approximation. On all surfaces we find an upshift of the surface d-band center upon lattice expansion. Still there is no general trend in the hydrogen adsorption energies at the high-symmetry sites and the dissociation barrier heights as a function of lattice strain for the low-index Cu surfaces in contrast to the predictions of the d-band model. It turns out that the adsorbate-induced change of the Cu local d-band density of states has to be taken into account in order to rationalize these results. As far as the oxygen-precovered Cu(1 0 0) surface is concerned, the strain-induced change in the hydrogen adsorption energies and dissociation barriers can simply be related to the increased hydrogen–oxygen distance upon lattice expansion.