A molecular beam investigation into the dynamics and kinetics of dissociative O2 adsorption on Pt{100}‐(1×1)

The dissociative chemisorption of oxygen on Pt{100}‐(1×1) has been investigated using supersonic molecular beams with incident translational energies between 0.04 and 0.90 eV over the surface temperature range 300 to 380 K. The adsorption process on the Pt{100}‐(1×1) surface is found to differ from that on the reconstructed Pt{100}‐hex‐R surface in both magnitude and mechanism. The initial dissociative sticking probability is ≳0.2 on the (1×1) surface for all beam energies and surface temperatures investigated, whereas on the reconstructed Pt{100}‐hex‐R surface, under corresponding conditions, the initial sticking probability never exceeds 0.003. The initial sticking probability on the (1×1) surface at first decreases with increasing incident energy and then increases as the incident energy exceeds 0.1 eV, in a manner typical of an adsorption process that is precursor mediated at low incident energies and direct at higher incident energies. Precursor‐mediated adsorption at low energies is also indicated b...