Facile Synthesis of Alkaline Ternary Deep Eutectic Solvents: Application for Effective and Reversible SO₂Uptake

Effective capture and recycling of SO₂are of great significance to environmental protection and high-value utilization. Herein, a promising strategy for effective and reversible capture of SO₂was proposed using alkaline ternary deep eutectic solvents (DESs) as absorbents. The absorbents consisting of choline chloride (ChCl), diethylenetriamine (DETA), and ethylene glycol (EG) with different molar ratios show a relatively lower viscosity and higher thermal stability. Here, ChCl/DETA/EG (1:1:2) could take out 0.87 g of SO₂/g of solvent at 298.15 K and 1.0 bar. Surprisingly, a SO₂absorption capacity of 0.53 g/g could still be gained under a lower SO₂partial pressure (0.2 bar).