Dynamics of the dissociative adsorption of CO 2 on Ni(100)

Abstract

The dynamics of the dissociative chemisorption of CO 2 on clean Ni(100) has been investigated using supersonic molecular beam and ultrahigh-vacuum techniques. The dissociative sticking probability, s 0, to form adsorbed CO and O, was found to be enhanced by three orders of magnitude by the addition of translational and vibrational energy to the incident CO 2 molecules. S 0 increased from 4 × 10 −4 to 0.15 as the component of translational energy normal to the surface was increased from 8 to 100 kJ/mol. Translational activation was also seen at a nozzle temperature of 1000 K, but s 0 was greater by a factor of two to ten at each translational energy, indicating the participation of vibrational excitation in activation of the molecule. The magnitude of the enhancement indicates that population of excited bending mode levels significantly increase the dissociative adsorption probability.