SIMS STUDY OF NO, CO ADSORPTION ON CU(100) AND CU(210) SURFACES

The adsorption of NO and CO on Cu(100) and Cu(210) at 110 K and the subsequent desorption/reaction have been studied by static SIMS, and complemented by XPS. After NO and CO coadsorption at 110 K, the major adsorbates are found to be NO2, N2O4, NO, NO3, CO, N and O adatoms. The dissociative adsorption of NO to form N and O adatoms is strongly enhanced on the stepped Cu(210) surface. Most of the molecular species desorb by 200 K upon heating the adlayer. On the stepped surface only, the formation of the isocyanate (-NCO) intermediate is observed, and is deduced to form via the reaction of adsorbed CO and N adatoms at step sites. At higher temperatures (200-300 K) the isocyanate intermediate decomposes to a cyanide (-CN) species.