The adsorption of CO2 was studied by molecular beam scattering on slightly and strongly reduced TiO2(110). The defect density has qualitatively been characterized by CO2 TDS. Two peaks were present in TDS, which could be assigned to CO2 adsorption on pristine and O vacancy sites. Interestingly, the initial reactivity, S0, towards CO2 adsorption decreased with increasing defect density and increased with increasing O pre-exposure. The latter was related to the vanishing of the defect structure in TDS. In contrast, H pre-exposure led to a decrease in S0 as well as the intensity of both TDS peaks decrease in sympathy.

Effect of Oxygen Vacancy Sites on CO2 Adsorption Dynamics - the Case of Rutile (1x1)-TiO2 (110). Funk, S., Hokkanen, B., Johnson, E., Burghaus, U.: Chemical Physics Letters, 2006, 422[4-6], 461-5