The adsorption of CO2 on Cu2O (111) oxygen-vacancy surface has been investigated by using the first-principles calculations based on the density functional theory (DFT). The geometry, adsorption energy, charge population and projected density of states (PDOS) were calculated. The results show dissociative adsorption of CO2 on the surface is thermodynamically unfeasible. The oxygen vacancy has the negative effects on the adsorption of CO2 at the coordinately unsaturated surface copper and oxygen (Cu-CUS and O-CUS) sites. Oxygen vacancies are the active sites. CO2 can be directly adsorbed and converted into CO2 delta- radical anion species at these sites. (C) 2013 Elsevier B.V. All rights reserved.