A theoretical study of the interaction of CO2 with hydroxylated alpha-alumina

Density functional molecular cluster calculations have been used to investigate the reaction of carbon dioxide (CO2) with hydroxylated alpha-alumina. The substrate has been modeled by considering the alpha-Al2O3(0001) surface, and the formation of bidentate chelating carbonate (BCC) and monodentate hydrogencarbonate (MHC) species has been considered. Adsorbate geometries, chemisorption enthalpies, and adsorbate vibrational parameters are computed and discussed. In agreement with experimental evidences [M. Casarin, D. Falcomer, A. Glisenti, A. Vittadini, Inorg. Chem. 42 (2003) 436], the most stable product is found to be a BCC surface complex.