Carbonate formation onp(4×4)-O/Ag(111)

High-resolution core-level spectroscopy and density-functional theory calculations have been used to investigate CO adsorption on the p(4 x 4) structure of oxidized Ag(111). CO adsorption with subsequent carbonate formation was observed at 100 K. The experimental results are consistent with calculations that reveal low activation barriers to form CO(2) and CO(3)(2-) from adsorbed CO. On the basis of a good match between calculated and experimental shifts in the Ag 3d and O 1s core-level binding energies, a model for a monolayer of carbonates on p(4 x 4)-O/Ag(111) is proposed.