School of Science, China University of Geosciences, Beijing 100083, China.
Molecules. 2021 Nov 26;26(23):7167. doi: 10.3390/molecules26237167.
Recently, deep eutectic solvents (DESs), a new type of solvent, have been studied widely for CO capture. In this work, the anion-functionalized deep eutectic solvents composed of phenol-based ionic liquids (ILs) and hydrogen bond donors (HBDs) ethylene glycol (EG) or 4-methylimidazole (4CH-Im) were synthesized for CO capture. The phenol-based ILs used in this study were prepared from bio-derived phenols carvacrol (Car) and thymol (Thy). The CO absorption capacities of the DESs were determined. The absorption mechanisms by the DESs were also studied using nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and mass spectroscopy. Interestingly, the results indicated that CO reacted with both the phenolic anions and EG, generating the phenol-based carbonates and the EG-based carbonates, when CO interacted with the DESs formed by the ILs and EG. However, CO only reacted with the phenolic anions when the DESs formed by the ILs and 4CH-Im. The results indicated that the HBDs impacted greatly on the CO absorption mechanism, suggesting the mechanism can be tuned by changing the HBDs, and the different reaction pathways may be due to the steric hinderance differences of the functional groups of the HBDs.
最近,深共晶溶剂(DESs)作为一种新型溶剂,在 CO 捕集方面得到了广泛的研究。在这项工作中,合成了由基于苯酚的离子液体(ILs)和氢键供体(HBD)乙二醇(EG)或 4-甲基咪唑(4CH-Im)组成的阴离子功能化深共晶溶剂,用于 CO 捕集。本研究中使用的基于苯酚的 ILs是由生物衍生的香芹酚(Car)和百里酚(Thy)制备的。测定了 DESs 的 CO 吸收能力。还使用核磁共振(NMR)、傅里叶变换红外(FTIR)和质谱研究了 DESs 的吸收机制。有趣的是,结果表明,当 CO 与由 ILs 和 EG 形成的 DES 相互作用时,CO 与 EG 同时与酚阴离子反应,生成基于苯酚的碳酸盐和基于 EG 的碳酸盐。然而,当 DESs 由 ILs 和 4CH-Im 形成时,CO 仅与酚阴离子反应。结果表明,HBD 对 CO 吸收机制有很大影响,表明可以通过改变 HBD 来调节该机制,而不同的反应途径可能是由于 HBD 官能团的空间位阻差异所致。