The Recombination of Gaseous Atomic Hydrogen with Adsorbed Hydrogen Atoms on a Planar Graphite surface

초록

We have studied the dynamics of energy-rich hydrogen molecules produced on a graphite surface using a classical trajectory procedure. The majority of incident atoms recombine with adsorbed atoms on a subpicosecond time scale with a significant portion of the reaction exothermicity depositing in the product vibration, which leads to a vibrational population inversion. The reaction probability is 0.37 at gas temperature 100 K and surface temperature 10 K. Vibrational excitation is strong when the incident gas atom H(g) first approaches close proximity of the surface and rebound toward the adatom H(ad) in a direct-mode reaction mechanism. H(g) reaching close to the surface at a large impact parameter tends to become trapped before rebounding to abstract H9ad), in which case the recombination proceeds through a complex-mode mechanism.