Deep Eutectic Solvents Consisting of 1‐Ethyl‐3‐methylimidazolium Chloride and Biobased 2‐Pyrrolidone for Reversible SO <sub>2</sub> Capture
Meng Lv, Dezhong Yang, Jie Chen
Abstract
Abstract Deep eutectic solvents are regarded as promising materials for capturing sulfur dioxide (SO 2 ), a toxic and acidic gas. Using biobased material to synthesis DESs is in agreement with the principles of sustainable chemistry. In this work, DESs consisting of biobased 2‐pyrrolidone (2‐Pyr) and solid ionic liquid 1‐ethyl‐3‐methylimidazolium chloride ([Emim][Cl]) were used to capture SO 2 . The SO 2 absorption capacities of three DESs, including [Emim][Cl]:2‐Pyr(2 : 1, molar ratio), [Emim][Cl]:2‐Pyr(1 : 1) and [Emim][Cl]:2‐Pyr(1 : 2), at various conditions were determined. The hydrogen bonding interactions between [Emim][Cl] and 2‐Pyr were studied using Fourier transform infrared (FTIR) technique. The thermal gravimetric analysis (TGA) was applied to study the thermal stability of DESs. The results indicated that these DESs based on 2‐Pyr could efficiently absorb SO 2 . In particular, [Emim][Cl]:2‐Pyr(2 : 1) revealed a high SO 2 uptake capacity of 1.36 g SO 2 /g solvent at 1.0 atm, and it also showed an attractive uptake capacity of 0.160 g SO 2 /g solvent even at 2000 ppm of SO 2. Moreover, the absorption mechanism was investigated by using FTIR and Nuclear magnetic resonance (NMR) spectra.