Eley-Rideal and Langmuir-Hinshelwood recombination coefficients for oxygen on silica surfaces

The energetics and dynamics of the Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-A) recombination reaction of oxygen atoms on beta cristobalite have been studied within a semiclassical collisional model, The calculated recombination coefficient gamma for the E-R reaction at T-s = 1000 K is in satisfactory agreement with the experimental value, whereas at T-s = 600 K a satisfactory agreement is found between the L-H gamma value and the experimental one. Results on the energy exchanges between the formed O-2 molecules and the silica surface are reported. Site-specific effects as well as the influence of the top layer surface structure are also pointed out and discussed.