Structure and stability of clean and adsorbate covered intermetallic PdGa surfaces: A first principles study

Abstract

In this work, using ab initio density functional theory based calculations we have studied the structure and stability of clean and hydrogen covered low-indexed (100) and (110) surfaces of intermetallic PdGa. We find that for the clean (100) surface, the stability of the surface terminations is independent of the surface preparation condition. On the contrary, at least three different types of surface terminations can be stabilized for the (110) surface by tuning the surface preparation conditions. Upon adsorbing molecular and atomic hydrogen on these surfaces, we find that: (a) at 450 K hydrogen adsorbs only at high hydrogen partial pressure and (b) the relative stability of the different surface terminations is unaffected by the presence of adsorbates.