A density functional theory (DFT) study of CO2 adsorption on Mg-rich minerals by enhanced charge distribution

In this study, we investigated the adsorption of multiple CO2 on Mg-rich minerals such as magnesium oxide (MgO) and olivine (MgSi2O4) surface in order to understand the adsorption mechanism of CO2 using density functional theory (DFT) approach. It is found that the energy required for the adsorption of CO2 onto Mg2SiO4 surface is 2.5 times (−1.30 eV) and 2.7 times (−0.70 eV) higher than that onto MgO surface for single and multiple CO2 chemisorption, respectively. The surface coverage (θ) of Mg2SiO4 surface is 1, which is four times higher than that of MgO surface. By analyzing the charge distribution of each atom of the MgO and Mg2SiO4 surfaces before and after the adsorption of CO2 molecules, we observed that charge redistribution occurs more readily in CO2–Mg2SiO4 than in CO2–MgO.