Efficient and Reversible Chemisorption of Carbon Dioxide with Dianionic-Functionalized Ionic Liquid-Based Solvents
Fangfang Li, Shaojuan Zeng, Yinge Bai, Haifeng Dong, Hui Wang, Xiaoyan Ji, Xiangping Zhang
Abstract
Developing carbon dioxide (CO2) capture technologies has caused worldwide interest because of the baneful influence of CO2 on climate change as a main greenhouse gas. Ionic liquids (ILs) are considered as potential absorbents for CO2 capture because of their unique properties compared with current amine-based solvents. In this work, new dianionic-functionalized IL-based solvents, bi(1,8-diazabicyclo[5.4.0]undec-7-ene) dimethylhydantoin/ethylene glycol ([(DBUH)2][Dhyd]/EG), were designed and prepared for efficient and reversible chemisorption of CO2. Among the absorbents, [(DBUH)2][Dhyd]/EG with a mass ratio of 5:5 exhibited not only a high CO2 absorption capacity of 0.11 g CO2/g absorbent at 20 °C and 0.10 MPa but also good recyclability. Spectroscopic characterizations and simulation calculations confirmed that the superior CO2 capacity may be attributed to the simultaneous reaction of CO2 with both the [Dhyd]2– anion and deprotonated EG. The excellent CO2 absorption and regeneration performance imply that [(DBUH)2][Dhyd]/EG solvents may have great industrial application potentials.