CONICET | Buscador de Institutos y Recursos Humanos

We study the dissociative dynamics of O2 molecules on the Ag 100 surface. Initially, the impinging molecules are either in the spin-triplet ground state or in the spin-singlet excited state. Themolecule-surface interaction is obtained in each case by constructing the six-dimensional potentialenergy surface PES from the interpolation of the energies calculated with spin-polarized and non-spin-polarized density functional theories, respectively. Classical trajectory calculationsperformed in both PESs show that O2 molecules initially in the spin-triplet ground state only dissociate for incidence energies above 1.05 eV. This result is consistent with molecular beamexperiments performed in this system. Interestingly, our results also suggest that for the spin-singlet O2 dissociation occurs even for incidence energies as low as 50 meV. We propose the use ofspin-singlet excited O2 molecules to improve the otherwise low dissociative reactivity of O2 at clean Ag 100.