Energy flows, recombination coefficients and dynamics for oxygen recombination on silica surfaces

The energetics and the dynamics of the Eley-Rideal and Langmuir-Hinshelwood recombination reaction of oxygen atoms on β-cristobalite have been studied within a semiclassical collisional model. The calculated recombination coefficient γ for the E-R reaction at TS=1000K is in good agreement with the experimental value, while at TS=600K a satisfactory agreement is found between the L-H γ value and the experimental one. Results on the energy exchanges between the formed O2 molecules and the silica surface are reported. Site specific effects as well as the influence of the top layer structure of the surface are also pointed out and discussed.