Zhang Jinrui, Lv Naixia, Chao Yanhong, Chen Linlin, Fu Wendi, Yin Jie, Li Hongping, Zhu Wenshuai, Li Huaming
Institute for Energy Research, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, PR China.
College of Biology and Chemistry, Xingyi Normal University for Nationalities, Xingyi, 562400, PR China.
J Mol Graph Model. 2020 Nov;100:107694. doi: 10.1016/j.jmgm.2020.107694. Epub 2020 Jul 22.
Carbon dioxide (CO) is one of the main factors leading to the greenhouse effect, so the capture of CO gas is currently a hot spot of research. Hollow silica-based porous ionic liquids (HS-liquids) are porous liquids containing cavities that are not only fluid but also have a high specific surface area and were used for the capture of CO. However, the mechanism of CO absorption by HS-liquids has not been studied. In this work, the mechanism of CO absorption by HS-liquids was systematic studied by density functional theory (DFT). First, five possible models for absorbing CO in HS-liquids were constructed and optimized. The interaction energies between HS-liquids and CO at different sites were obtained. Moreover, the effects of HS-liquids with different degrees of polymerization of polyethylene glycol and different alkyl chain lengths on CO absorption were also investigated. Results show that the strongest absorption site locates near the polyethylene glycol unit. Then, the electrostatic potential (ESP) and reduced density gradient (RDG) methods were employed to further understand the interaction nature between them. The results show that hydrogen bonding dominates the weak interaction between the HS-liquid and CO.
二氧化碳（CO₂）是导致温室效应的主要因素之一，因此CO₂气体的捕集是当前研究的热点。中空二氧化硅基多孔离子液体（HS-液体）是一种含有空腔的多孔液体，不仅具有流动性，而且比表面积大，可用于捕集CO₂。然而，HS-液体吸收CO₂的机理尚未得到研究。在这项工作中，通过密度泛函理论（DFT）对HS-液体吸收CO₂的机理进行了系统研究。首先，构建并优化了HS-液体中吸收CO₂的五种可能模型。获得了HS-液体与CO₂在不同位点的相互作用能。此外，还研究了聚乙二醇聚合度不同和烷基链长度不同的HS-液体对CO₂吸收的影响。结果表明，最强的吸收位点位于聚乙二醇单元附近。然后，采用静电势（ESP）和密度降低梯度（RDG）方法进一步了解它们之间的相互作用本质。结果表明，氢键主导了HS-液体与CO₂之间的弱相互作用。
