CO2 adsorption on TiO2(110) rutile: Insight from dispersion-corrected density functional theory calculations and scanning tunneling microscopy experiments

Adsorption of CO2 on the rutile( 110) surface was investigated using dispersion-corrected density functional theory and scanning tunneling microscopy ( STM). On the oxidized surface the CO2 molecules are found to bind most strongly at the five-fold coordinated Ti sites adopting tilted or flat configurations. The presence of bridging oxygen defects introduces two new adsorption structures, the most stable of which involves CO2 molecules bound in tilted configurations at the defect sites. Inclusion of dispersion corrections in the density functional theory calculations leads to large increases in the calculated adsorption energies bringing these quantities into good agreement with experimental data. The STM measurements confirm two of the calculated adsorption configurations. (C) 2011 American Institute of Physics. [doi:10.1063/1.3561300]