Strain and coordination effects in the adsorption properties of early transition metals

Strain and coordination effects in the adsorption on early transition metals were studied using density functional theory. We show that, in contrast to late transition metals, early transition metal surfaces with a less than half-filled local d-band exhibit lower adsorption energies upon lattice expansion and on low-coordinated sites, in agreement with predictions based on the d-band model. This demonstrates that the d-band model can be extended to early transition metals. Implications of these results for hydrogen storage materials are discussed.