A molecular beam study of the NO interaction with Pt(111)

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Abstract
Using angle and time resolved molecular beam techniques, an investigation of the low coverage adsorption‐desorption kinetics of NO on Pt(111) is made. The experiments are carried out over a crystal temperature range of 300 K<TsTs≳500 K, the sticking probability s≳0.9. NO adsorbs molecularly with little dissociation (<5%). The desorption rate is found to be strongly dependent on the incident beam flux and trace amounts of chemisorbed oxygen (<1%) on the surface. These findings suggest that steps play the dominant role in low coverage kinetics for a nominally flat crystal. We present a model which incorporates the effect of steps, explains the nonlinearity of the desorption kinetics, and reconciles the disagreement between these results and previous molecular beam studies.