Calculation of CO_2 Adsorption on SrTiO_3(100) with Density Functional Theory

Based on the first-principle of density functional theory(DFT),adsorption of carbon dioxide(CO2) on both SrO-and TiO2-terminated SrTiO3(100) surfaces was simulated and the adsorption energies and structure parameters were obtained under several different models,which would be valuable for disclosing the adsorption mechanism and structural stability.It was found that the structures which C atom of CO2 adsorbed on SrTiO3(100) surface were more stable,especially for co-adsorption of both C and O atoms on TiO2-terminated,while the remaining adsorption models unstable.The analysis of the mulliken charges and the density of state(DOS) to such the stable adsorption models showed that the adsorption of CO2 on SrTiO3(100) surface was dominated by the electronic on SrTiO3(100) surface transitions to CO2.The bent structure CO2-anion was formed by CO2 catching an electron,and was accompanied by the C-O bond became longer,so as to achieve the purpose of the activation of CO2.