Energy disposal in collisions of nitric oxide with molecular adlayers on transition metal single crystal surfaces: Rotational energy disposal

The dynamics of the scattering of nitric oxide (NO) from well-characterized and ordered layers of carbon monoxide (CO) and ethylidyne (CCH3) adsorbed on a Pt(111) substrate have been investigated through resonance-enhanced multiphoton ionization (REMPI) measurements of the rotational quantum state distributions of the scattered NO molecules for a range of incident NO translational energies between 10 and 50 kJ mol(-1) from scattering substrates at 108 and 300 K. The measurements reveal that, where in principle the interaction potential resembles that of the NO-Ag(111) system more so than that of the NO-Pt(111) system, the scattering differs remarkably from that expected from a weakly bound system in that it occurs both into a trapping-desorption channel and a direct inelastic channel. Experimental data are presented that indicate both an incident translational energy dependence and substrate surface temperature dependence of the scattering, which is interpreted in terms of a hard-cube model. (C) 2000 American Institute of Physics. [S0021-9606(00)70343-6].