THE ROLE OF CHLORINE IN OXYGEN-ADSORPTION ON AG(111)

The effect of chlorine adsorption on oxygen adsorption on Ag(111) was studied with HREELS and TPD. Oxygen adsorption on Ag(111) and Ag(111) exposed to a low chlorine dose produces mainly atomic oxygen species at 170 K and room temperature. On Ag(111) exposed to a high chlorine dose and a surface with the same chlorine adsorption conditions, but followed by removal of chlorine, a molecular oxygen species was the only product of oxygen adsorption at 170 K or room temperature. The altered behavior of oxygen adsorption is due to surface defects created via chlorine adsorption. It was also found that these surface defects increase the adsorption rate of oxygen and promote the diffusion of oxygen into the subsurface. © 1993 Academic Press, Inc.