Two-dimensional quantum dynamics of O2 dissociative adsorption on Ag(111)

We have investigated the quantum dynamics of O-2 dissociative adsorption on a Ag(111) surface. We performed the calculations with a Hamiltonian where the O-2 translationalmotion is perpendicular to the surface and for O-2 vibrational energy. We found that dissociative adsorption occurs with an incident translational energy below the expected activation barrier, while the translational-energy dependence for adsorption probabilities is a smooth sigmoid. Thus, there are non-negligible tunneling effects in the dissociative adsorption that are affected by the activation barrier width. Moreover, the incident translational energies at the inflection points of the adsorption probabilities shift lower with an increase in vibrational quantum numbers of the incident O-2. Thus, there is significant energy transfer and coupling from vibration to translational motion. The vibrational energy assists the O-2 dissociative adsorption via a vibrationally assisted sticking effect.