Ionic Liquid Functionalized 3D Mesoporous FDU-12 for Effective SO2 Capture

The emission of SO2 from the combustion of fossil fuels leads to many environmental issues. The incorporation of ionic liquids (ILs) on porous supports to produce supported ionic liquids is an effective technology for SO2 capture. However, blockage of pore channels is one of the main problems of this technology, which results in a substantial decrease of absorption capacity. Herein, a novel type of ionic liquid, 1-methyl-3-(3-triethoxysilylpropyl) imidazolium tetrazolate, functionalized large pore sized 3D mesoporous FDU-12 sorbents has been synthesized through a chemical grafting method. The as-prepared materials are characterized using SAXS, N2 adsorption, TEM, XPS, elements analysis, EDS mapping, and TGA and then the performance of these materials to capture SO2 is studied. The IL@FDU-12 materials are found to exhibit a high absorption capacity of SO2 up to 8.19 mmol SO2/g-sorbent (i.e., 524.2 mg/g) and a fast absorption rate (ca. 6 min is needed to reach equilibrium) at 25 °C and 1 bar since blockage of pore channels is effectively avoided and the IL is highly dispersed in the channels. These materials can also be used for the effective capture of CO2 (1 bar) and low content of SO2 (10%). Moreover, they have excellent thermal stability and can be reused in many absorption/desorption cycles without loss of the high absorption capacity and fast sorption/desorption rate.