Carbon dioxide capture from air using ionic liquid hybrid metal–organic frameworks

Abstract

Mitigating climate change induced by global warming is anticipated to necessitate the large-scale deployment of carbon dioxide (CO₂) removal strategies. In this study, MPImBr ionic liquid was impregnated for the first time into the Mg/DOBDC MOF (a metal–organic framework (MOF) built from Mg(OAc)₂·4H₂O linked by 2,5-dioxido-1,4-benzenedicarboxylate (DOBDC) ligands), yielding a series of stable ionic liquid hybrid materials for CO₂ capture at ambient temperature (25 °C). A comprehensive review of the room-temperature CO₂ capture performance of the composite was presented, and the effect of IL content on the structural changes of the composite was investigated. Subsequently, the water adsorption and CO₂ adsorption cycle stability of the material were tested under humid air conditions. Finally, the adsorption mechanism was discussed through computational simulations and characterisation methods. Research findings indicated that the metal nodes within the MOF interact with halide anions in ionic liquids, thereby increasing the number of active metal sites and consequently enhancing the adsorption of CO₂.