Coordination Polymer Electrocatalysts Enable Efficient CO-to-Acetate Conversion.

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Chemistry

Background:

• Electrochemical conversion of carbon dioxide and carbon monoxide (CO) to multi-carbon products is a key strategy for sustainable fuel and chemical production.
• Acetate is a valuable product, but its profitable electrosynthesis requires highly efficient catalysts.

Purpose of the Study:

• To develop and evaluate a novel coordination polymer (CP) catalyst for the selective electrosynthesis of acetate from CO.
• To assess the catalyst's performance in terms of efficiency, selectivity, stability, and product concentration.

Main Methods:

• Synthesis of a coordination polymer (CP) catalyst comprising Cu(I) and benzimidazole units linked by Cu(I)-imidazole coordination bonds.
• Integration of the CP catalyst into a cation exchange membrane-based membrane electrode assembly (MEA).
• Electrochemical testing in flow cells to evaluate CO reduction to acetate.

Main Results:

• The CP catalyst achieved a 61% Faradaic efficiency for selective CO to acetate reduction at -0.59 V vs. RHE and 400 mA cm⁻².
• Stable acetate electrosynthesis was maintained for 190 hours in the MEA.
• Direct collection of concentrated acetate (3.3 M) was achieved with 50% CO utilization and 15% energy efficiency at 250 mA cm⁻².

Conclusions:

• The developed Cu(I)-benzimidazole CP catalyst demonstrates high efficiency and selectivity for acetate electrosynthesis from CO.
• The MEA design facilitates stable operation and concentrated product collection, paving the way for sustainable chemical production.