Multilayer Electrolyzer Stack Converts Carbon Dioxide to Gas Products at High Pressure with High Efficiency

Area of Science:

• Electrochemistry
• Chemical Engineering
• Materials Science

Background:

• Electrochemical reduction of carbon dioxide (CO2) offers a sustainable pathway for mitigating greenhouse gas emissions and producing valuable chemicals.
• Existing technologies often rely on liquid catholytes, which can complicate product separation and scalability.

Purpose of the Study:

• To present a novel zero-gap, multilayer electrolyzer for continuous, gas-phase electrochemical CO2 reduction.
• To demonstrate the scalability and efficiency of this new electrolyzer design for CO production.

Main Methods:

• Development and testing of a multilayer zero-gap electrolyzer cell for gas-phase CO2 electrolysis.
• Optimization of CO2 pressure and gas distribution for enhanced performance.
• Evaluation of partial current densities, faradaic efficiency, cell voltage, and CO2 conversion efficiency.

Main Results:

• Achieved routine CO partial current densities exceeding 250 mA cm-2, reaching 300 mA cm-2 at 10 bar CO2 pressure with ~95% faradaic efficiency.
• Demonstrated scalable operation with uniform gas distribution across multiple layers.
• Reported high CO2 conversion efficiency up to 40% and low cell voltage of -3.0 V.

Conclusions:

• The developed multilayer zero-gap electrolyzer enables efficient and scalable electrochemical CO2 reduction to CO.
• This technology presents a promising approach for CO2 utilization, offering high performance metrics and simplified operation without liquid catholytes.