Study of chemisorption on silver surfaces using ultraviolet photoelectron spectroscopy (UPS)

Ultraviolet photoelectron spectroscopy (UPS) was used to study the chemisorption of halogens on stepped [3(111) × (100)] and low-index (111) silver surfaces. The initial rate of halogen adsorption using CHCl3 exposure on the silver stepped surface is approximately twice that on the low-index surface. This indicates that steps play an important role in chemisorption even on metals with a low density of states at the Fermi level. The adsorbate-induced levels on silver were correlated with halogen p valence orbitals using model extended Hückel calculations. Changes in the silver d band are interpreted as due to p−d orbital interactions.