Research on CO2 adsorption performances of metal-doped (Ca, Fe and

Capturing CO2 from the atmosphere is key to solving the global warming problem/transforming it into chemical products. Therefore, in this study, CO2 adsorption features of Ca/Fe/Al doped MgO are investigated via density functional theory (DFT) calculations. With adsorption structures, adsorption energies, partial density of states (PDOS), electron cloud distribution and transition state (TS) processes, CO2 adsorption mechanisms of doped MgO for sustainable and recyclable utilization are clearly demonstrated. According to calculation results, the average CO2 adsorption energies of doped MgO increase in sequence of Ca-doping, Fe-doping and Al-doping, which corresponds to relevant chemical valence (+2 for Ca, +2/+3 for Fe and +3 for Al). In the meantime, it is discovered that the more doping atoms are embedded in MgO, the higher average CO2 adsorption energies of doped MgO are, which further verifies the adsorption enhancement effects of doping atoms. What is more, TS energy barriers of CO2 adsorbing on some sites of Al-doped MgO are calculated to investigate chemisorption structures being transformed into strong physisorption, which could help to cut down energy consumption during cyclic use of adsorbents. The results of this study would supply significant information for realizing massive and sustainable CO2 adsorption application of MgO in some industries.