Ionic liquid

Electrode

Organic chemistry

Process engineering

Mathematics

Dissolution

Engineering

Catalysis

Physical chemistry

Econometrics

Flammability

Inorganic chemistry

Eutectic system

Chemistry

Materials science

Alloy

Chemical engineering

Electrochemistry

Green chemistry

Volatility (finance)

Green Chemical Engineering

Green solvents are one of the hot topics of green chemistry. Ionic liquids (ILs) and deep eutectic solvents (DESs) are deemed as green solvents to a certain extent, and they have been applied in many areas, such as dissolution, separation, catalysis, electrochemistry and material synthesis. However, the greenness of ILs and DESs should be revisited because more and more evidences have shown that they are not always green. In this perspective, besides the reported merits, the disadvantages and problems of some ILs and DESs, such as instability, volatility, hygroscopicity, toxicity, flammability, regenerability, cost, energy consumption and impurities are discussed. Moreover, 13 strategies to avoid the disadvantages of ILs and DESs and to increase the greenness are proposed. Comparison of the greenness of ILs and DESs is further conducted. This perspective provides some new viewpoints on the greenness of ILs and DESs.

Revisiting greenness of ionic liquids and deep eutectic solvents