Plane-wave density functional theory calculations were performed to investigate the binding and diffusion of H on three flat Ni surfaces, Ni(100), Ni(110), and Ni(111), and two stepped Ni surfaces, Ni(210) and Ni(531). On each surface, the favored adsorption sites were identified by considering the energy and stability of various binding sites and zero-point energy corrections were computed. Binding energies were compared with experimental and theoretical results from the literature. Good agreement with experimental and previous theoretical data was found. At surface coverages where adsorbate-adsorbate interactions were relatively weak, the binding energy of H was similar on the five Ni surfaces studied. Favorable binding energies were observed for stable surface sites, while subsurface sites have unfavorable values relative to the gas phase molecular hydrogen. Minimum energy paths for H diffusion on Ni surfaces and into subsurface sites were constructed.

Chemisorption and Diffusion of Hydrogen on Surface and Subsurface Sites of Flat and Stepped Nickel Surfaces. B.Bhatia, D.S.Sholl: Journal of Chemical Physics, 2005, 122[20], 204707 (8pp)