Dynamics of H₂Formation on a Graphite Surface

초록

We have studied the dynamics of energy-rich hydrogen molecules produced on a graphite surface using a classical trajectory procedure. The recombination reaction efficiently takes place on a subpicosecond time scale with most of the reaction exothermicity depositing in the product vibration, which leads to a strong vibrational population inversion. The total reaction cross section is 10.9Ų at gas temperature 100 K and surface temperature 10 K. Vibrational excitation is particularly strong when H(g) reaching close to the surface tends to become trapped before abstracting H(ad) from below, in which case the recombination proceeds through a complex-mode mechanism. A significant fraction of trapped H(g) remains on the surface while the dissociating H(ad) recedes from the surface with a high translational energy.