Halide-free deep eutectic solvents with low viscosity and corrosion for efficient SO₂ capture and conversion under...

Area of Science:

• Green chemistry
• Catalysis
• Materials science

Background:

• Sulfur dioxide (SO2) is a major pollutant requiring effective capture and conversion strategies.
• Deep eutectic solvents (DESs) offer tunable properties for chemical applications.
• Developing efficient and environmentally friendly SO2 capture methods is crucial.

Purpose of the Study:

• To synthesize and characterize novel halogen-free deep eutectic solvents (DESs).
• To evaluate the SO2 capture capacity and catalytic activity of the synthesized DESs.
• To elucidate the underlying mechanisms of SO2 capture and conversion.

Main Methods:

• Synthesis of eight halogen-free DESs with low viscosity.
• Measurement of SO2 solubility in DESs under various conditions.
• Catalytic evaluation in the cycloaddition reaction between SO2 and epoxides.
• Spectroscopic and theoretical investigations (e.g., DFT) to understand reaction mechanisms.

Main Results:

• The synthesized DESs demonstrated excellent SO2 solubility (up to 1.2514 g g-1 at 20 °C and 1 bar).
• High catalytic activity was observed in the cycloaddition of SO2 and epoxides.
• Synergistic effects between hydrogen bond donors (HBDs) and hydrogen bond acceptors (HBAs) were identified.

Conclusions:

• Halogen-free DESs are effective media for SO2 capture and catalytic conversion.
• The DESs exhibit promising performance for green chemistry applications.
• Understanding the synergistic HBD-HBA interactions is key to optimizing DES design.