Deep Eutectic Solvents Consisting of 1‐Ethyl‐3‐methylimidazolium Chloride and Biobased 2‐Pyrrolidone for Reversible SO2 Capture. Issue 24 (24th June 2020) - Lv, Meng
Abstract: Deep eutectic solvents are regarded as promising materials for capturing sulfur dioxide (SO2 ), 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 SO2 . The SO2 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 SO2 . In particular, [Emim][Cl]:2‐Pyr(2 : 1) revealed a high SO2 uptake capacity of 1.36 g SO2 /g solvent at 1.0 atm, and it also showed an attractive uptake capacity of 0.160 g SO2 /g solvent even at 2000 ppm of SO2. Moreover, the absorption mechanism was investigated by using FTIR and Nuclear magnetic resonance (NMR) spectra. Abstract : Deep eutectic solvents based on 1‐ethyl‐3‐methylimidazolium chloride ([Emim][Cl]) and biobased 2‐pyrrolidone (2‐Pyr) can be easily prepared for the capture of SO2 . The intermolecular hydrogen bonds between [Emim][Cl] and 2‐Pyr were investigated. [Emim][Cl]:2‐Pyr (2 : 1, molar ratio) exhibited a high capacity up to 0.160 g SO2 /g solvent at 2000 ppm of SO2, which was due to the strong charge transfer interactions between S atom of SO2 and anion Cl − . [Emim][Cl]:2‐Pyr (2 : 1) also performed a high reversibility