The adsorption of CO and NO on a hydrogen presaturated Ni(510) surface
has been studied with electron energy loss spectroscopy (HREELS). We
find that the initial CO adsorption at the step sites is blocked and t
hat a mixed on-top-bridge adsorption on the terraces is altered to exc
lusively on-top. NO still adsorbs at the steps but with a much less we
akened internal bond. A strongly bent NO adsorption state on the terra
ces is inhibited. At saturation coverages both CO and NO adsorb on ter
race and step sites. For all coverages the terrace adsorption is, for
both CO and NO, essentially identical to the behaviour observed on the
Ni(100)p(1 x 1)H surface.