Charged Microdroplets as Microelectrochemical Cells for CO₂ Reduction and C-C Coupling

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• Traditional electrochemical interfaces (solid-liquid, solid-liquid-gas) have limitations.
• Charged microdroplets present unique liquid-gas interfaces with intense electric fields.
• These environments offer novel opportunities for electrochemical reactions.

Purpose of the Study:

• To propose and validate charged microdroplets as microelectrochemical cells (MECs).
• To investigate the synthesis of ethanol via CO2 reduction and C-C coupling using molecular catalysts in MECs.
• To elucidate the relationship between MEC properties (size, charge density) and reaction selectivity.

Main Methods:

• Utilizing electrospray to generate charged microdroplets.
• Employing molecular catalysts for electron transfer and stabilization.
• Conducting in situ mass spectrometry to identify intermediates and products.

Main Results:

• Successfully synthesized ethanol from CO2 reduction and C-C coupling within charged microdroplets.
• Demonstrated that molecular catalysts enhance electron longevity and enable multielectron CO2 reduction.
• Established a correlation between MEC size/charge density and reaction selectivity.
• Identified key reaction intermediates and oxidation products, clarifying the mechanism.

Conclusions:

• Charged microdroplets effectively function as microelectrochemical cells (MECs).
• This approach enables efficient multielectron CO2 reduction to valuable products like ethanol.
• MEC properties critically influence electrochemical reaction outcomes, offering tunable selectivity.
• Charged microdroplets represent a promising platform for developing advanced electrochemical systems.