Adsorption geometries of CO on Cu (211)

The adsorption of CO on Cu (211), serving as model system for the adsorptio n of CO in stepped surfaces, has been investigated using electron energy lo ss spectroscopy (EELS). At a surface temperature of 110 K, CO adsorbs nondi ssociatively and is drawn exclusively to descending step sites in this syst em. On-top and bridge sites are sequentially populated with the CO axis bei ng perpendicular to the surface. In addition, at low coverage, a molecular state is observed, for which the CO axis is strongly inclined. (C) 1999 Ame rican Institute of Physics. [S0021-9606(99)70421-6].