# Ionic Liquids as Interfacial Media for Metal-Free Electrochemical CO2 Reduction in Water

## TL;DR

This paper shows how ionic liquids can help convert CO2 into useful chemicals without using metal catalysts, offering a sustainable approach for reducing carbon emissions.

## Contribution

The study introduces ionic liquids as a metal-free strategy to polarize CO2 and enhance its electrochemical reduction in water.

## Key findings

- Ionic liquids polarize CO2 and improve its electrochemical response at a glassy carbon interface in aqueous conditions.
- The efficiency of the electrochemical response depends on the chemical identity of the ionic liquids used.
- IL-induced molecular polarization is proposed as a general strategy to activate nonpolar small molecules for sustainable synthesis.

## Abstract

The electrochemical carbon dioxide reduction reaction
(CO2RR) in water offers a sustainable pathway to mitigate
carbon emissions
while generating value-added chemicals. Most conventional CO2RR systems rely heavily on metal-based catalysts. Beyond traditional
metal-based catalyst design, attention has increasingly shifted to
understanding how the electrochemical microenvironment and the electrode–electrolyte
interface influence CO2RR. Ionic liquids (ILs), widely
regarded as green solvents, have previously been employed as electrolytes
or cocatalysts in metal-catalyzed systems. Yet, the ability of ILs
to facilitate CO2RR at metal-free interfaces in aqueous
media remains underexplored. Here, we demonstrate that ILs polarize
CO2 and facilitate CO2 electrochemical response
at a glassy carbon interface under aqueous conditions, while simultaneously
functioning as electrolytes. Spectroscopic, electrochemical, and computational
analyses reveal that ILs interact with CO2, thereby increasing
its dipole moment. This interaction suggests a favorable environment
for CO2 polarization that correlates with the observed
electrochemical response. The response efficiency depends on the chemical
identity of the ILs, highlighting the tunability of this IL-based
system. These findings redefine the functional role of ILs in CO2RR, establishing IL-induced molecular polarization as a potential
strategy for promoting the reactivity of otherwise inert molecules.
More broadly, this work introduces IL-driven dipole modulation as
a general approach for enabling reactivity of nonpolar small molecules,
with implications for sustainable chemical synthesis.