室温熔盐中CO_2的捕集与电化学资源化转化

Capture and Electrochemical Conversion of CO_2 in Room-Temperature Molten Salts

室温熔盐(离子液体)具有优良的物理及化学特性、较宽的电化学窗口和较高的电导率,种类众多并易于通过调节阴阳离子组成对物理化学性质进行设计调控,是一类新型的重要化学反应媒质.本文总结评述了室温熔盐作为吸收介质(电解质)捕集CO_2与电化学资源化转化方面的研究进展,逐次讨论了传统离子液体、功能化离子液体、离子液体/有机溶液复配体系、离子液体支撑膜、聚合物基离子液体对CO_2吸收捕集的原理和特性,对CO_2在室温熔盐中电化学转化制备高附加值产品(CO、环状碳酸酯、碳酸二甲酯)的电化学反应途径、反应特征和转化效率进行了评述,进一步展望了离子液体在绿色高效CO_2捕集与电化学资源化领域的发展前景.

Room-temperature molten salts （ionic liquids, ILs） have excellent physical and chemical properties such as wide electrochemical window and high electrical conductivity. Moreover, ILs can be conveniently designed and tailored to meet the requirement of applications due to the variable cations and anions composition. This paper re- viewed the recent progress of ionic liquids as medium for capture and electrochemical conversion of carbon dioxide. The absorption principle and performances of CO2 capture in ionic liquids based media were summarized based on the clue of the development of CO2-capture ILs systems, namely, in an order of traditional ionic liquids, functional ionic liq- uids, ionic liquids-organics mixture, supported ionic liquid membrane and polymer-based ionic liquids. Different from the electrochemical reduction of CO2 in aqueous solution, the reduction products in ionic liquids are mainly CO, cyclic carbonate and dimethyl carbonate, depending on the composition of ILs and raw materials. The mechanism and con- version efficiency of the electrochemical reaction are also briefly reviewed. Furthermore, outlook of the green and high efficiency process of CO2 capture and conversion in ILs is prospected.