Molecular adsorption and dissociation of CO2 on TiO2 anatase (001) activated by oxygen vacancies
- 69 Downloads
A study on the influence of oxygen vacancies on the anatase (001) surface on the CO2 adsorption process is presented. For its realization, density functional theory (DFT) was used under the Perdew–Burke–Ernzerhof (PBE) generalized gradient and the spin-polarized approximations. Hubbard-U corrections and van der Waals interactions were also included. Three different types of oxygen vacancies were investigated at different sites on the anatase (001) surface; the formation energies in each case were 67.05, 113.84, and 93.16 kcal/mol, respectively. We identified a type of oxygen vacancy that could favor both the CO2 adsorption and dissociation. The differences on CO2 adsorption properties are due to electronic and structural causes, such as midgap states (Ti3+ polarons species) and changes in the structural properties on the TiO2 surface, generated upon the introduction of an oxygen vacancy. It is concluded that oxygen vacancies can play an important role in both CO2 adsorption and dissociation.
KeywordsCO2 TiO2 Dissociation Vacancies Adsorption
N.S. and J.A.M. want to thank the ICTP for providing access to its computational resources. N.S. also wants to thank ICETEX for their support through the “Profesores Invitados” program. L.A.A.V. acknowledges the receipt of a fellowship from the ICTP-TRIL Programme, Trieste, Italy. Finally, J.A.M. and L.A.A.V. also want to thank the Fondo Nacional de Financiamiento para la Ciencia, la Tecnología y la Innovación Francisco José de Caldas, for financial support through contract 299-2016, as well as the Vicerrectoría de Investigaciones of the Universidad de Cartagena for its support through research grants.
- 5.Belmabkhout Y, Serna R, Sayari A (2010) Adsorption of CO2-containing gas mixtures over amine-bearing pore-expanded MCM-41 silica: application for gas purification. Ind sEng Chem 49:359–365Google Scholar
- 14.Wang J, Li S, Zhao Z, Zhou D, LU A, ZHANG W (2016) Density functional theory study of CO2 adsorption in amine-functionalized carbonaceous materials. Acta Phys Chim Sin 32(7):1666–1673Google Scholar
- 34.Scandolo S, Giannozzi P, Cavazzoni C, Gironcoli S, Pasquarello A, Baroni S (2005) First-principles codes for computational crystallography in the quantum-ESPRESSO package. Z Kristallogr 220:574–579Google Scholar