Effects of Surface Orientations of Cr2O3 on CO2 Adsorption: a DFT approach

Anand Kumar (1, 2) , Francois Ropital (1) , Theodorus de Bruin (1) , Boubakar Diawara (2)

1 IFPEN - IFP Energies nouvelles
2 ENSCP - Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL

In the context of corrosion of stainless steel being in contact with supercritical CO 2 , during the transportation step of CO 2 sequestration process, we have studied the adsorption of CO 2 molecule on different Cr 2 O 3 surfaces terminations: (), (̅) and (̅ using density functional calculations. Upon CO 2 adsorption, the formation of physisorbed and chemisorbed species are found to be dependent on different surface terminations. The analyses of the optimized geometrical parameters, vibrational frequencies and atomic charges revealed the formation of a carboxylate species and a carbonate on O layer terminated-(, (̅ and a carbonate species on Cr layer-(̅) facets, respectively. The chemical bonding analysis depicts the formation of a covalent bond between the carbon and surface oxygen (O s) atom and between the oxygen atom of the CO 2 molecule and Cr atom. Additionally, the electron density distributions (calculated from Bader's theory) show a net electron transfer from the surface to the CO 2 molecule, turning the latter into an ionic species. The calculated adsorption energies and CO s vibrational frequencies are in good agreement with the available experimental data and emphasize the formation of carbonates for non-(surface termination.

Mots clés: CO2 adsorption; Chromium oxide surfaces; Carboxylates; Surface carbonates; Periodic DFT; DOS; Bader charge analysis; Vibrational frequency

Domaines: Chimie; Sciences de l'environnement

Anand Kumar, Francois Ropital, Theodorus de Bruin, Boubakar Diawara. Effects of Surface Orientations of Cr2O3 on CO2 Adsorption: a DFT approach. Applied Surface Science, 2020, 25, pp.147127. ⟨10.1016/j.apsusc.2020.147127⟩. ⟨hal-02953984⟩