Facile Synthesis of Alkaline Ternary Deep Eutectic Solvents: Application for Effective and Reversible SO₂ Uptake

Effectivecapture and recycling of SO2 are of greatsignificance to environmental protection and high-value utilization.Herein, a promising strategy for effective and reversible captureof SO2 was proposed using alkaline ternary deep eutecticsolvents (DESs) as absorbents. The absorbents consisting of cholinechloride (ChCl), diethylenetriamine (DETA), and ethylene glycol (EG)with different molar ratios show a relatively lower viscosity andhigher thermal stability. Here, ChCl/DETA/EG (1:1:2) could take out0.87 g of SO2/g of solvent at 298.15 K and 1.0 bar. Surprisingly,a SO2 absorption capacity of 0.53 g/g could still be gainedunder a lower SO2 partial pressure (0.2 bar). Besides,the prepared absorbents also exhibit rapid equilibration time andsatisfied reusability, providing a potential alternative strategyfor the effective and reversible elimination of SO2.