Adsorption Kinetics And Dynamics Of Small Organic Molecules On A Silica Wafer: Butane, Pentane, Nonane, Thiophene, And Methanol Adsorption On Sio_2/si(1 1 1)

摘要

The adsorption kinetics (by thermal desorption spectroscopy) and adsorption dynamics (by molecular beam scattering) have been determined for a number of alkanes, methanol, thiophene, and water on a silica wafer-SiO_2/Si(1 1 1). No indications for bond activation were present, i.e., all probe molecules adsorb molecularly obeying 1st order kinetics. The coverage-dependent heat of adsorption has been determined accordingly. The adsorption dynamics are precursor-mediated with Kisliuk-like shapes of the adsorption probabilities at low impact energies and adsorbate-assisted adsorption at large impact energies.