Visualization of CO₂ electrolysis using optical coherence tomography

Area of Science:

• Electrochemistry
• Chemical Engineering
• Optical Imaging

Background:

• Electrolysers are promising for converting carbon dioxide (CO2) into valuable chemicals.
• Effective tools for monitoring reactions within electrolysers are limited.
• Understanding reaction dynamics is crucial for optimizing CO2 conversion efficiency.

Purpose of the Study:

• To develop and demonstrate an electrolysis optical coherence tomography (OCT) platform.
• To visualize chemical reactions and component behavior in a CO2 electrolyser.
• To provide insights into the mechanisms of CO2 reduction.

Main Methods:

• Designed and implemented an OCT platform for 3D imaging of electrolysers.
• Recorded 12 hours of footage of a CO2 electrolyser under continuous flow conditions.
• Applied current densities ranging from 50-800 mA cm-2 during electrolysis.

Main Results:

• Visualized reactants, intermediates, and products of CO2 conversion.
• Captured dynamic movements of cathode and membrane components during electrolysis.
• Correlated carbon monoxide (CO) production with specific regions of CO2-membrane-catalyst contact.

Conclusions:

• The developed OCT platform effectively visualizes reactions in CO2 electrolysers.
• The platform provides high-resolution spatial and temporal data on electrochemical processes.
• This technology can significantly aid in tracking and optimizing reactions in continuous flow electrochemical reactors.