Adsorption mechanism of CO2 on the single atom doped or promoted Li4SiO4(0 1 0) surface from first principles

Abstract

The removal of CO2 by lithium silicate is of great significance to alleviate global warming. In order to understand the micro mechanism of the interaction between CO2 and lithium silicate, density functional theory model is developed to explore the effects of B, Al and Ga as dopants and promoters on the CO2 adsorption performance of lithium silicate. Adsorption energy, charge transfer and desorption barrier of CO2 are calculated. It is found that CO2 combines with the lattice oxygen atom on the surface with C atom, and the adsorption energy is −1.91 eV. The doping of B, Al and Ga to Si atom in lithium silicate intensifies the adsorption of CO2 and inhibits the desorption of CO2. Doping of B, Al and Ga to Li atom has the opposite effect. These results provide the interaction mechanism between CO2 and lithium silicate and show the strategy to modify lithium silicate for CO2 capture.