Abstract:

As a greenhouse gas, CO₂ is a precious C₁ resource. In order to achieve the strategic goal of “carbon peaking and carbon neutrality”, it is imperative to vigorously develop carbon dioxide utilization and storage technologies. Ionic liquids are green solvents composed of organic cations and organic or inorganic anions, while deep eutectic solvents (DESs) are a novel kind of green solvent formed by hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs) via hydrogen bonds. Ionic deep eutectic solvents (iDES) are new green solvents. They not only have similar chemical properties with ionic liquids, such as low vapor pressure, wide liquid temperature range, high thermochemical stability, and tunable structure properties, but also have the characteristics of hydrogen bonds. In recent years, a series of iDES containing choline, quaternary ammonium salts, and quaternary phosphonium salts were reported as green sorbents, solvents, and catalysts for highly efficient capture and transformation of CO₂. However, the application and mechanism of iDES in the direction of CO₂ conversion have not been systematically summarized. Therefore, this article reviews iDES for CO₂ conversion during the last two decades (2003—2023), focusing on the thermal catalysis, biocatalysis, electrocatalysis of CO₂ to obtain a variety of high-value chemicals, such as cyclic carbonate, carbamate, methanol, CO and CaCO₃. Additionally, the mechanism of iDES on the catalytic reaction of CO₂ is discussed. Moreover, the development directions and challenges of DESs for CO₂ conversion are discussed.

Key words: ionic liquid, deep eutectic solvent, carbon dioxide, catalysis, thermal catalysis, electrochemistry, biocatalysis

摘要：

CO₂作为一种温室气体，是一种宝贵的C₁资源，为实现“碳达峰、碳中和”战略目标，大力发展二氧化碳利用与封存技术是当务之急。离子液体是由有机阳离子和有机或无机阴离子组成的绿色溶剂，而低共熔溶剂是由氢键受体和氢键供体通过氢键形成的一种新型的溶剂。离子液体基低共熔溶剂不仅拥有离子液体相似的性质，如低饱和蒸气压、宽液温范围、高热化学稳定性、结构性能可调控等，还具备了低共熔溶剂的氢键特性。本文综述了离子液体基低共熔溶剂在CO₂热催化、电催化、生物催化领域的应用，并分析了各种催化方式中的CO₂转化机理和影响因素，展望了低共熔溶剂应用于转化CO₂的前景，对目前该领域的发展所面临的主要问题和进一步的研究工作提出了建议。

关键词: 离子液体, 低共熔溶剂, 二氧化碳, 催化（作用）, 热催化, 电化学, 生物催化