By using density functional theory calculations, an investigation was made of the adsorption and diffusion of O species on the reduced (110) surface. It was found that molecular O2 strongly bonded not only to O vacancies, but also to Ti(5c) neighbors; due to delocalization of unpaired electrons arising from the removal of neutral bridging O. The results showed that molecular O2 could jump across an O vacancy and diffused along a Ti(5c) row with moderate barriers. On the other hand, atomic O diffusion along a Ti(5c) row was unlikely below 300K, because of the relatively higher probability of O-O formation from interaction with an adjacent bridging O(2c) atom.

Dynamics of Oxygen Species on Reduced TiO2 (110) Rutile. Y.Wang, D.Pillay, G.S.Hwang: Physical Review B, 2004, 70[19], 193410 (4pp)