First-Principle Study of Adsorption and Desorption of Chlorine on Cu(111) Surface. Does Chlorine or Copper Chloride Desorb?

First-principle density-functional calculations have been applied to study the interaction of molecular chlorine with the (111) plane of copper. Using transition-state search method, we considered the elementary processes (Cl${}_2$ dissociation, adsorption, diffusion, association and desorption) on the chlorinated Cu(111) surface. A systematic study of possible desorption pathways has been carried out for different species (Cl, Cl${}_2$, CuCl, CuCl${}_2$, and Cu) at various chlorine coverage. As a result, we concluded that chlorine monolayer irrespective of the coverage desorbs in the form of CuCl molecules from step edges.