Sulfite-Assisted Acetate Conversion from CO Electroreduction.

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Efficient acetate production via CO electroreduction is hindered by low selectivity at high reaction rates, competing with hydrogen and other C2+ products.
• Electrolyte engineering offers a viable strategy to control the reaction microenvironment and enhance selectivity.

Purpose of the Study:

• To investigate the effect of sulfite addition on CO electroreduction to acetate using copper catalysts.
• To improve the Faradaic efficiency and partial current density for acetate production.

Main Methods:

• Electrochemical reduction of CO using synthesized Cu(200) and commercial Cu(111) catalysts in KOH electrolytes with and without sulfite (SO3^2-).
• Analysis of reaction products and catalytic performance, including Faradaic efficiency and partial current density.

Main Results:

• Sulfite addition enhanced CO-to-acetate conversion by forming a S-O bond with C2 intermediates, improving selectivity on both Cu(200) and Cu(111) catalysts.
• The Cu(200) catalyst with sulfite modification achieved a 63.6% Faradaic efficiency at -0.6 A·cm^-2 and a peak partial current density of 1.52 A·cm^-2.
• These results surpass previously reported values for both CO and CO2 electroreduction to acetate.

Conclusions:

• Introducing nucleophilic oxyanions like sulfite into electrolytes is an effective strategy for regulating the microenvironment in CO electroreduction.
• This approach enables high-performance, industrial-current-density electrosynthesis of acetate from CO.
• The findings suggest a promising pathway for sustainable acetate production.