Highly Efficient and Reversible SO₂ Capture by Surfactant-Derived Dual Functionalized Ionic Liquids with Metal Chelate Cations

Abstract

A series of dual functionalized ionic liquids with metal chelate cations from surfactant and alkali metal salt were designed, prepared, and used for SO₂ capture. The effect of metal ions, coordination number, anionic structures, temperature, and pressure on SO₂ absorption was investigated. The interaction of these functionalized ionic liquids with SO₂ was explained by spectroscopic investigation. The results showed that these metal-containing ionic liquids exhibited high absorption capacity through a combination of physical and chemical interaction of SO₂ with basic anions and ether-containing cations as well as excellent reversibility (21 recycles). Considering the easy preparation, low cost, and excellent performance, these dual functionalized metal-containing ionic liquids provide significant improvements over traditional ionic liquids, indicating the promise for industrial application in SO₂ capture