Ionic liquid/ metal organic framework composites as a new class of materials for CO2 capture: Present scenario and future perspective

Carbon dioxide (CO2) emissions have gained worldwide attention due to their potential impact on climate change. To mitigate the impact of global warming, significant reduction in atmospheric CO2 and its net zero emission by 2050 are required. Among the tested strategies, the most viable and economical approach would be (i) CCS (carbon capture and storage) and/or (ii) CCU (carbon capture and utilization). Due to their intriguing features like huge surface areas, variable pore size, high porosities and acceptable chemical and thermal stabilities, metal organic frameworks (MOFs) have been actively researched in several fields from their first synthesis. The physicochemical properties and application-oriented specific features within the MOFs are recently introduced through forming the MOF-IL composites through introducing ionic liquids (ILs) as cavity occupiers into the pores of MOFs. This will impact the properties of MOFs particular their gas affinities and physicochemical properties of MOFs. Recent research has demonstrated that IL/MOF composites outperform pure MOFs in a multitude of fields, such as gas storage, membrane-based gas separation, adsorption, ionic conductivity and catalysis to name a few. In the present review, we present a detailed summary of current breakthroughs in the formation of IL/MOF composites and provide a comprehensive summary on CO2 capture ability, CO2/CH4 and CO2/N2 selectivity of IL/MOF composite.