Ab initio Investigation of Hydrogen Atom Adsorption and Absorption on Pd(110) Surface

Ab initio investigation based on density functional theory is performed to determine the behavior of H atom diffusion in Pd(110) surface to the first and second subsurface layers. Potential energy surface is constructed to determine the local minima and activation barriers of H pathways. Contribution of the relaxation of surface atoms in the binding energies of H and activation barriers along the diffusion paths, as well as the zero point energy corrections are also included in this work. The binding energies of H in the second subsurface layer are lower compared to its binding energies in the first subsurface layer and this is attributed to the interaction of H with the surface atoms and the differences in interlayer spacing of the surface layers. Comments on the adsorbate induced Pd(110) (1 x 2) missing/adding-row reconstruction phenomenon is also given with reference to the observed results in this work as H is absorbed from the surface to the first subsurface layer.