First-principles prediction of NO2 and SO2 adsorption on MgO/(Mg0.5Ni0.5)O/MgO(100)

Abstract

Developing high-performance adsorbents for NO2 and SO2 is a significant step in reducing air pollution. In this study, using first-principles modeling, NO2 and SO2 adsorption on MgO/(Mg0.5Ni0.5)O/MgO(1 0 0) was theoretically predicted. Adsorption of NO2 was stronger than that of SO2 on the MgO/(Mg0.5Ni0.5)O/MgO(1 0 0) surface. Both structural and chemical changes were applied to MgO/(Mg0.5Ni0.5)O/MgO(1 0 0) in order to investigate strategies for improving the strength of adsorption of these gases on the MgO/(Mg0.5Ni0.5)O/MgO(1 0 0) system. NO2 and SO2 adsorption on MgO/(Mg0.5Ni0.5)O/MgO(1 0 0) was found to be tunable using the applied strain and certain promoters, such as Ca and Sr. The approach with the promoter more effectively enhanced the strength of NO2 and SO2 adsorption on MgO/(Mg0.5Ni0.5)O/MgO(1 0 0) than the approach with the applied strain. The interactions between the adsorbate (i.e., NO2 and SO2) and the MgO/(Mg0.5Ni0.5)O/MgO(1 0 0)) surface were further elucidated through an investigation of the density of states and Bader charge.