The effects of surface geometry and island formation on alkali-promoted surfaces: The coadsorption of CO and K on Ni(110)

Publisher Website
Google Scholar
Abstract
The room temperature coadsorption of CO and low coverages of K on Ni(110) has been studied with LEED,thermal desorptionspectroscopy, and high resolution electron energy loss spectroscopy (HREELS). The results indicate that two distinct CO species coexist on the surface. A strongly perturbed species is observed that exhibits behavior commonly attributed to alkali‐promoted surfaces: a higher thermal desorption temperature and a lower C–O stretch frequency of 1660 cm− 1. A very weakly perturbed species is observed that behaves in nearly identical fashion to CO adsorbed on the clean surface. We propose that the appearance of the distinct alkali‐promoted species in HREELS is the result of the formation of ordered surface structures of fixed alkali:CO stoichiometry, and suggest that this relationship may be a general one.