The reactivity of CO2 on the MgO(100) surface

Abstract

We investigate the adsorption of CO₂ over an MgO(001) terrace, as calculated using an embedded cluster method. We find adsorbed geometries for CO₂ on the perfect surface with energies which differ appreciably from previous studies, and observe that it is polarization of the surface rather than the inclusion of electron correlation which leads to this discrepancy. Our results suggest that both monodentate and tridentate carbonate formation on the MgO(001) surface are favourable processes, with the monodentate structure being of lower energy. Adsorption of CO₂ is found to be favourable at both F⁰ and F⁺ terrace sites, but not at F²⁺. We also find that chemisorption at oxygen vacancy sites with a single localized electron (F⁺) could provide a route for the conversion of CO₂ to other products, and that this system may be a useful model for other, more effective catalysts.