Cui Guokai, Zhao Ning, Wang Jianji, Wang Congmin
Henan Key Laboratory of Green Chemistry, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007, China.
Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, Shanghai, 200062, China.
Chem Asian J. 2017 Nov 2;12(21):2863-2872. doi: 10.1002/asia.201701215. Epub 2017 Oct 11.
A new strategy involving the computer-assisted design of substituted imidazolate-based ionic liquids (ILs) through tuning the absorption enthalpy as well as the basicity of the ILs to improve SO capture, CO capture, and SO /CO selectivity was explored. The best substituted imidazolate-based ILs as absorbents for different applications were first predicted. During absorption, high SO capacities up to ≈5.3 and 2.4 molSO2 mol could be achieved by ILs with the methylimidazolate anions under 1.0 and 0.1 bar (1 bar=0.1 MPa), respectively, through tuning multiple N⋅⋅⋅S interactions between SO and the N atoms in the imidazolate anion with different substituents. In addition, CO capture by the imidazolate-based ILs could also be easily tuned through changing the substituents of the ILs, and 4-bromoimidazolate IL showed a high CO capacity but a low absorption enthalpy. Furthermore, a high selectivity for SO /CO could be reached by IL with 4,5-dicyanoimidazolate anion owing to its high SO capacity but low CO capacity. The results put forward in this work are in good agreement with the predictions. Quantum-chemical calculations and FTIR and NMR spectroscopy analysis methods were used to discuss the SO and CO absorption mechanisms.
探索了一种新策略，即通过调节基于咪唑盐的离子液体（ILs）的吸收焓和碱度来进行计算机辅助设计，以改善SO₂捕获、CO₂捕获以及SO₂/CO₂选择性。首先预测了作为不同应用吸收剂的最佳基于咪唑盐的离子液体。在吸收过程中，通过调节SO₂与不同取代基咪唑盐阴离子中N原子之间的多个N∙∙∙S相互作用，分别在1.0和0.1 bar（1 bar = 0.1 MPa）下，具有甲基咪唑盐阴离子的离子液体可实现高达≈5.3和2.4 mol SO₂/mol的高SO₂容量。此外，通过改变离子液体的取代基，基于咪唑盐的离子液体对CO₂的捕获也可轻松调节，4-溴咪唑盐离子液体表现出高CO₂容量但低吸收焓。此外，具有4,5-二氰基咪唑盐阴离子的离子液体由于其高SO₂容量但低CO₂容量，对SO₂/CO₂具有高选择性。这项工作中提出的结果与预测结果高度吻合。使用量子化学计算以及傅里叶变换红外光谱和核磁共振光谱分析方法来讨论SO₂和CO₂的吸收机制。
