A first principles study of CO2 adsorption on α-SiO2(001) surfacesElectronic supplementary information (ESI) available: Additional figures, details on computational methodology, and key structures are given. See DOI: 10.1039/c5cp02279g

In this work, using first principles calculations, an analysis of CO 2 interaction with cleaved and reconstructed α-SiO 2 (001) surfaces was performed. We showed that CO 2 could strongly interact with a cleaved surface forming CO3-like configurations. Here, the binding energy per CO 2 molecule depends strongly on CO 2 surface coverage and can reach −2.35 eV. Despite this, even with CO 2 molecules, the cleaved surface has a substantially higher surface energy than that of the reoptimized "dense" surface. This observation is also consistent with molecular dynamics simulations. Because of this, for thermodynamically stable system, the interaction of CO 2 molecules with a α-SiO 2 (001) surface should be treated as the physisorption of CO 2 molecules on the reoptimized "dense" surface with the binding energy varying from −0.26 eV for single CO 2 molecule adsorption to −0.32 eV per molecule for monolayer coverage. CO 2 interaction with cleaved and reconstructed α-SiO 2 (001) surfaces is studied using first principles calculations.