Exploring electrochemical windows of room-temperature ionic liquids: a computational study.

Area of Science:

• Electrochemistry
• Materials Science
• Computational Chemistry

Background:

• Room-temperature ionic liquids (RTILs) are recognized as sustainable solvents with low volatility and flammability.
• Their wide electrochemical windows make them suitable for electro-catalysis, electro-plating, and separations.
• Understanding RTIL electrochemical stability and degradation is key to enhancing their applications.

Purpose of the Study:

• To computationally investigate the electrochemical properties of various RTILs.
• To evaluate different computational approaches for predicting electrochemical windows.
• To identify factors influencing RTIL electrochemical stability.

Main Methods:

• Employed four computational approaches, ranging from gas-phase to explicit solvation models.
• Calculated electrochemical properties for diverse RTILs.
• Validated computational predictions against experimental data.

Main Results:

• Implicit and explicit solvent models reliably predict experimental electrochemical window data.
• The simplest computational model showed significant accuracy limitations.
• Electrochemical window stability generally increases in the order: imidazolium < ammonium < pyrrolidinium < phosphonium.

Conclusions:

• Computational modeling, particularly with implicit/explicit solvent models, is a reliable method for predicting RTIL electrochemical windows.
• This validated methodology can be used for screening ionic liquids for electrochemical applications.
• The findings provide a basis for optimizing RTIL selection for improved efficiency and applicability.