Binding of oxygen with titanium dioxide on singlet potential energy surface: An ab initio investigation

Ab initio calculations have been carried out to investigate interaction of titanium dioxide TiO₂ with oxygen O₂ in ground triplet and excited singlet states. On a singlet potential energy surface (PES) formation of a stable compound of titanium peroxide TiO₄ is revealed which should appear in reaction of TiO₂ with singlet oxygen without activation barrier. This peroxide is lower in energy than the ground state of two individual molecules TiO₂ + 3O₂ by 34.6 kcal/mol. Location of conical intersection between triplet and singlet PESs of TiO₂-O₂ is also investigated.