Coadsorption properties of CO 2 and H 2 O on TiO 2 rutile (110): A dispersion-corrected DFT study

• Main Authors: Sorescu, DC, Lee, J, Al-Saidi, WA, Jordan, KD
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2012
• Subjects: Carbonic acid
• Online Access: http://d-scholarship.pitt.edu/16183/; http://d-scholarship.pitt.edu/16183/1/licence.txt

Adsorption and reactions of CO 2 in the presence of H 2O and OH species on the TiO 2 rutile (110)-(1×1) surface were investigated using dispersion-corrected density functional theory and scanning tunneling microscopy. The coadsorbed H 2O (OH) species slightly increase the CO 2 adsorption energies, primarily through formation of hydrogen bonds, and create new binding configurations that are not present on the anhydrous surface. Proton transfer reactions to CO 2 with formation of bicarbonate and carbonic acid species were investigated and found to have barriers in the range 6.1-12.8 kcalmol, with reactions involving participation of two or more water molecules or OH groups having lower barriers than reactions involving a single adsorbed water molecule or OH group. The reactions to form the most stable adsorbed formate and bicarbonate species are exothermic relative to the unreacted adsorbed CO 2 and H 2O (OH) species, with formation of the bicarbonate species being favored. These results are consistent with single crystal measurements which have identified formation of bicarbonate-type species following coadsorption of CO 2 and water on rutile (110). © 2012 American Institute of Physics.