Interaction of CO with Oxygen Adatoms on TiO2(110)

The interaction between CO and O adsorbed on TiO2(110) has been investigated using scanning tunneling microscopy (STM), electron stimulated desorption (ESD), temperature programmed desorption (TPD), and density functional theory (DFT). Coadsorption of CO and O produces CO-O and CO-O-CO surface complexes via weak attractive interaction as revealed by STM and DFT. The effect of the adsorbates interaction can also be observed in two ensemble-averaged techniques, ESD and TPD, strongly supporting the STM and DFT results. The CO molecules adsorbed near chemisorbed O cause a similar to 70% decrease in the O+ ion yield in ESD. The interaction between CO and O is considered to be electrostatic in nature due to the charge rearrangement upon chemisorption.