Alkaline Ionic Liquid Microphase Promotes Deep Reduction of CO₂ on Copper

Area of Science:

• Electrochemistry
• Catalysis
• Sustainable Energy

Background:

• Electrochemical reduction of carbon dioxide (CO2) to multicarbon (C2+) products is crucial for sustainable energy storage and carbon neutrality.
• Achieving high C2+ product faraday efficiency (FE) at high current densities remains a significant challenge.

Purpose of the Study:

• To develop an effective strategy for enhancing CO2 electroreduction to C2+ products.
• To investigate the role of immobilized alkaline ionic liquids on copper catalysts.

Main Methods:

• Immobilization of an alkaline ionic liquid onto a copper electrode surface.
• Electrochemical characterization including cyclic voltammetry and chronoamperometry.
• Analysis of product distribution and faraday efficiency at various current densities.

Main Results:

• A C2+ FE of 81.4% was achieved at a current density of 0.9 A·cm-2 with 47.4% energy conversion efficiency.
• Even at a high current density of 1.8 A·cm-2, a C2+ FE of 71.6% was obtained.
• Mechanistic studies revealed the ionic liquid enhances CO2 accumulation, activation, and dimerization, facilitating C2+ formation.

Conclusions:

• Immobilized alkaline ionic liquids on copper are highly effective for promoting CO2 electroreduction to C2+ products.
• The strategy enables high efficiency at industrially relevant current densities, advancing sustainable energy solutions.
• The ionic liquid plays a multifaceted role in optimizing the catalytic process for C2+ product generation.