Water Interactions with Terminal Hydroxyls on TiO2(110)

A combination of scanning tunneling microscopy and density functional theory has been used to investigate 'the interactions between water molecules and terminal hydroxyls (OH1's) adsorbed on the TiO2(110) surface at 300 K. We show that OH1's have. a significant effect on the water reactivity. Two distinctive reaction pathways are unraveled depending on the whether H2O and OHt are on the same or adjacent Ti rows. The underlying reaction mechanisms involve proton transfer from H2O to OHt leading to the formation of new H2O molecules, accompanied by O scrambling and along- or across-row apparent motion of OHt's.