Oxygen-induced surface reconstructions on curved Ag(111)

Abstract

The adsorption of oxygen and the resultant O-induced surface reconstructions are key components in heterogeneously catalyzed reactions on silver metal surfaces. O uptake and reconstructions on planar Ag(111) are well-characterized, and in this paper, we show that curved Ag(111) features similar O adsorption and reconstructions. Through a systematic scanning tunneling microscope study of a curved Ag(111) single crystal exposed to gas-phase atomic oxygen at a temperature of 525 K, we observed Oad and, upon higher coverages, saw p(4×4) and p(4×5√3) reconstructions form on both the A-type and B-type steps. Exposures at low temperatures (< 500 K) resulted in the formation of subsurface oxygen and the appearance of a stripe pattern and amorphous phase on the surface. Upon heating, stable surface reconstructions were formed. Although the geometric arrangement of atoms along the steps were different, A-type and B-type steps formed the same reconstructions. In addition, the B-type steps also saw the formation of several different features atop the oxygen reconstructions.