A density functional study of NO2 adsorption on perfect and defective MgO (1Â 0Â 0) and Li/MgO (1Â 0Â 0) surfaces

► Adsorption properties of Li atom on various sites of MgO (1 0 0) surface. ► The characteristics of the NO2 molecule adsorption on various sites of MgO (1 0 0) surface before and after supported Li atom. ► The presence of Li atom enhances the adsorption processes of NO2 on MgO(O2−) substrate surfaces. ► The existence of Li atom does not sustain the adsorption processes of NO2 on MgO (Fs and Fs+). ► The presence of Li atom converts the adsorption of NO2 on MgO(O2−) substrate surfaces from physisorption to chemisorptions.