Eley-Rideal formation of H2 involving one of two para-chemisorbed H atoms on a graphite surface

Following the work of Rougeau et al. [N. Rougeau, D. Teillet-Billy, V. Sidis, Chem. Phys. Lett. 431 (2006) 135] we study the title reaction when a gas phase H atom impinges on one of two para-chemisorbed H atoms on a graphite surface. DFT calculations of the PES and QCT dynamics calculations are carried out for the on top approach. We find that the studied reaction is barrier-less. The vibrational energy of the nascent H2 molecule is centered on the v = 5 level which is significantly lower than what is found for the singly chemisorbed H atom case; also, the energy left in the C atom vibration at the surface is somewhat larger.