The interaction of NO with stepped Rh surfaces

The dissociation of NO has been studied on a number of Rh single crystal surfaces consisting of (111) and (100) terraces by means of thermal desorption spectroscopy. The influence of both the surface structure and the presence of atomic nitrogen and atomic oxygen on the dissociation of NO have been investigated. The thermal decomposition of NO, which manifests itself by the formation of N-2, is not surface structure dependent at saturation coverage. The presence of N-ad and O-ad inhibit the dissociation of NO. At an excess of O-ad. NO is formed via recombination of N-ad and O-ad atoms. Atomic nitrogen is more stable on (100) terraces than on (111) terraces. No effect of steps on the N-2 and NO TDS spectra was observed. (C) 1997 Elsevier Science B.V.