Can charge-modulated metal-organic frameworks achieve high-performance CO2 capture and separation over H2, N2, and CH4?

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Article numbere202101674
Number of pages11
Journal / PublicationChemSusChem
Volume15
Issue number3
Online published7 Dec 2021
Publication statusPublished - 8 Feb 2022

Abstract

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=hexa-aminobenzene) metal-organic frameworks (MOFs) were evaluated as charge-modulated CO2 capture and separation materials by using density functional theory and grand canonical Monte Carlo simulations. The results showed that each TM-HAB presented a high electrical conductivity and structural stability when injecting charges. The CO2 adsorption energy increased 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 were better charge-modulated CO2 capture materials with less structure deformation based on energy decomposition analyses. The kinetic process demonstrated that considerably low energy consumptions of 0.911 and 1.589 GJ ton−1 CO2 were observed for a complete adsorption–desorption cycle on Co-HAB and Ni-HAB. All charged MOFs, especially Co-HAB and Ni-HAB, exhibited higher CO2 adsorption energies and adsorption capacities than those of H2, N2, and CH4, thereby exhibiting high CO2 selectivities. Interaction analysis confirmed that the injecting charges had a more pronounced enhancement in the coulombic 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 low energy consumption.

Research Area(s)

  • adsorption, charge modulation, CO2 capture, metal-organic frameworks, selectivity