Scalable and Depurative Zirconium Metal-Organic Framework for Deep Flue-Gas Desulfurization and SO2 Recovery

Deep SO2 removal and recovery as industrialfeedstockare of importance in flue-gas desulfurization and natural-gas purification,yet developing low-cost and scalable physisorbents with high efficiencyand recyclability remains a challenge. Herein, we develop a viablesynthetic protocol to produce DUT-67 with a controllable MOF structure,excellent crystallinity, adjustable shape/size, milli-to-kilogramscale, and consecutive production by recycling the solvent/modulator.Furthermore, simple HCl post-treatment affords depurated DUT-67-HClfeaturing ultrahigh purity, excellent chemical stability, fully reversibleSO(2) uptake, high separation selectivity (SO2/CO2 and SO2/N-2), greatly enhancedSO(2) capture capacity, and good reusability. The SO2 binding mechanism has been elucidated by in situ X-ray diffraction/infrared spectroscopy and DFT/GCMC calculations.The single-step SO2 separation from a real quaternary N-2/CO2/O-2/SO2 flue gas containingtrace SO2 is implementable under dry and 50% humid conditions,thus recovering 96% purity. This work may pave the way for futureSO(2) capture-and-recovery technology by pushing MOF synthesestoward economic cost, scale-up production, and improved physiochemicalproperties.

Automated summary

In this study, a viable synthetic protocol was developed to produce DUT-67 with controllable MOF structure, excellent crystallinity, adjustable shape/size, and large-scale production. Simple HCl post-treatment resulted in depurated DUT-67-HCl with ultrahigh purity, excellent chemical stability, fully reversible SO2 uptake, and high separation selectivity. This research has important implications for future SO2 capture and recovery technology.