LAUSR

CO2 capture and separation by using charge-modulated adsorbent materials is a promising strategy to reduce CO2 emissions. Herein, three TM-HAB (TM = Co, Ni, and Cu; HAB = hexaaminobenzene) metal-organic frameworks (MOFs) are evaluated as charge-modulated CO2 capture and separation materials by using density functional theory and grand canonical Monte Carlo simulations. The results show that each TM-HAB presents a high electrical conductivity and structural stability when injecting charges. The CO2 adsorption energy increases from 0.211 to 2.091 eV on Co-HAB, 0.262 to 2.119 eV on Ni-HAB, and 0.904 to 2.803 eV on Cu-HAB, respectively, with the increase in charge state from 0.0 to 3.0 e- . Co-HAB and Ni-HAB are better charge-modulated CO2 capture materials with less structure deformation based on energy decomposition analyses. The kinetic process demonstrates that the considerably low energy consumptions of 0.911 and 1.589 GJ/ton CO2 are observed for a complete adsorption/desorption circle on Co-HAB and Ni-HAB. All charged MOFs, especially Co-HAB and Ni-HAB, exhibit high CO2 adsorption energies and adsorption capacities than those of H2 , N2 and CH4 , thereby exhibiting high CO2 selectivities. Interaction analysis confirms that the injecting charges have a more pronounced enhancement in the coulomb interactions between CO2 and MOFs. The results of this work highlight Co-HAB and Ni-HAB as promising charge-modulated CO2 capture and separation materials with controllable CO2 capture, high selectivity, and considerably low energy consumption.