Amino-functionalization enhanced CO₂ reduction reaction in pure water

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Electrochemical reduction of carbon dioxide (CO2RR) is key for carbon neutrality.
• Alkali cations improve CO2RR but cause electrode precipitation, reducing stability.
• Pure water electrolytes in CO2 electrolyzers avoid precipitation but lower catalyst performance.

Purpose of the Study:

• To develop a catalyst modification that mimics alkali cations in pure water for CO2RR.
• To enhance CO2 adsorption and proton interaction while suppressing the hydrogen evolution reaction (HER).

Main Methods:

• Amino modification of catalyst surfaces.
• Utilizing pure water as the anolyte in a zero-gap CO2 electrolyzer.
• Performance evaluation via faradaic efficiency (FECO) and long-term stability tests.

Main Results:

• Achieved 95.5% FECO at 250 mA cm-2 using amino-modified catalysts in pure water.
• Demonstrated over 180 hours of stable operation without maintenance.
• Amino groups effectively mimicked alkali cation functions, enhancing CO2 adsorption and suppressing HER.

Conclusions:

• Amino-modified catalysts offer a stable and efficient solution for CO2RR in pure water.
• This strategy effectively addresses the limitations of traditional electrolytes in CO2 electrolyzers.
• The findings present a promising pathway for cost-effective carbon capture and utilization technologies.