Phonon investigation on the interaction of hydrogen on the missing row Pt (110)-(1x2) surface

Abstract

The phonon calculations of hydrogen when adsorbed on the missing row Pt(110)-(1x2) surfaceusing the Ultrahigh Vacuum (UHV) model were studied. The calculations were based on a combinationof Density Functional Theory (DFT) and the approximation of hydrogen vibrations on thesurface. The harmonic vibration of H on the Pt surface was used for the calculation in this study. Atthe hydrogen coverage of 1ML for the model surface (when H completely covering the Pt surface),the interaction formed at the edge of the first layer (short bridge - R) was the most stable. The lessstable positions were recorded as the bridge position between two atoms on a horizontal row inthe second layer (trough - T), the top position of the second surface layer - fcc (F), the bridge positionof the second surface layer - hcp (F'), and the least stable position was the top position of thefirst layer (T'). When accounting the quantum calculation for the model, the adsorption energy ofhydrogen at the short bridge position increased by 90 meV, and the stable adsorption order of hydrogenchanged with the most stable positions ware R, T, T', F', F respectively. This demonstratesdthe significant influence of quantum effects on the adsorption model.