Metal organic frameworks immobilized polyacrylonitrile fiber mats with polyethyleneimine impregnation for CO2 capture

Carbon dioxide (CO2) is a main greenhouse gas contributing to global warming issues. Considerable attention has been generated to reduce the atmospheric concentration of CO2. In the present work, we have prepared series of metal organic framework (MOF) immobilized polyacrylonitrile (PAN) fiber mats with different wt% loading of MOF particles via electrospinning technique. The existence of well-defined framework of MOFs in PAN fibers were confirmed by X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectra. The structural properties were analyzed by N-2 sorption isotherms at 77 K showing increased surface area and pore volume with increase in MOF loading. CO2 adsorption capacities for PAN/ZIF-8 and PAN/HKUST-lmats with 60% loading showed the maximum capacities of 0.55 mmol/g and 2.55 mmol/g respectively at 298 K and 1 bar, which reached to 70% and 80% of capacities for ZIF-8 and HKUST-1 powders. With addition of polyethyleneimine (PEI) in PAN/ZIP-8 (60%) fibers, CO2 adsorption capacity was significantly increased by 45%, resulting in a large increase in CO2/N-2 sorption selectivity from 6 to 54.