Scalable and Depurative Zirconium Metal-Organic Framework for Deep Flue-Gas Desulfurization and SO 2 Recovery.

Deep SO 2 removal and recovery as industrial feedstock are of importance in flue-gas desulfurization and natural-gas purification, yet developing low-cost and scalable physisorbents with high efficiency and recyclability remains a challenge. Herein, we develop a viable synthetic protocol to produce DUT-67 with a controllable MOF structure, excellent crystallinity, adjustable shape/size, milli-to-kilogram scale, and consecutive production by recycling the solvent/modulator. Furthermore, simple HCl post-treatment affords depurated DUT-67-HCl featuring ultrahigh purity, excellent chemical stability, fully reversible SO 2 uptake, high separation selectivity (SO 2 /CO 2 and SO 2 /N 2 ), greatly enhanced SO 2 capture capacity, and good reusability. The SO 2 binding mechanism has been elucidated by in situ X-ray diffraction/infrared spectroscopy and DFT/GCMC calculations. The single-step SO 2 separation from a real quaternary N 2 /CO 2 /O 2 /SO 2 flue gas containing trace SO 2 is implementable under dry and 50% humid conditions, thus recovering 96% purity. This work may pave the way for future SO 2 capture-and-recovery technology by pushing MOF syntheses toward economic cost, scale-up production, and improved physiochemical properties.