CO₂ electrolysis to multicarbon products in strong acid

Area of Science:

• Electrochemistry
• Catalysis
• Sustainable Chemistry

Background:

• Carbon dioxide electroreduction (CO2R) offers a pathway for converting emissions into valuable products.
• Current CO2R methods in neutral or alkaline media show low efficiency for multicarbon products and significant carbonate formation.
• Acidic electrolytes are limited by dominant hydrogen evolution, hindering CO2R.

Purpose of the Study:

• To develop an efficient CO2R process in acidic electrolytes.
• To overcome the challenge of hydrogen evolution in acidic conditions for CO2R.
• To enhance CO2 activation and product selectivity in acidic electrocatalysis.

Main Methods:

• Utilizing copper-based electrocatalysts in acidic electrolytes (pH <1).
• Employing a strategy to concentrate potassium cations near electrocatalytic sites.
• Operating the electrochemical reactor at a current density of 1.2 A/cm² and a cell voltage of 4.2 V.

Main Results:

• Achieved a single-pass CO2 utilization of 77% in acidic conditions.
• Demonstrated a 50% conversion efficiency toward multicarbon products (ethylene, ethanol, propanol).
• Successfully suppressed hydrogen evolution, enabling efficient CO2R.

Conclusions:

• Concentrating potassium cations is a viable strategy to accelerate CO2 activation in acidic media.
• This method significantly improves CO2R efficiency and selectivity for valuable products.
• The findings pave the way for more effective carbon capture and utilization technologies.