INFLUENCE OF COADSORBED H ON THE ADSORPTION OF CO AND NO ON A NI(510)SURFACE

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.