Efficient Separation of Trace SO2 from SO2/CO2/N2 Mixtures in a Th-Based MOF

The emission of sulfur dioxide (SO2) from flue gases is harmful since trace SO2 impairs human health and the natural environment. Therefore, developing new metal organic frameworks (MOFs) to capture this toxic molecule is of great importance in flue gas desulfurization. In this work, we synthesized a new MOF, namely, ECUT-Th-60, which consists of two distinct channels (3.0 Å × 4.1 Å and 2.3 Å × 4.8 Å). It shows SO2 uptakes of around 2.5 mmol/g at 0.1 kPa and 3.35 mmol/g at 1 bar, which are higher than those of CO2 and N2 under identical conditions. Both simulated and experimental breakthrough tests proved that ECUT-Th-60 can separate trace SO2 from SO2/CO2 mixtures. Impressively, complete separation of SO2 from SO2/CO2/N2 mixtures under both dry and humid conditions was also proved in ECUT-Th-60, predicting its potential application in flue gas desulfurization.