A Nature-Inspired Solution for Water Management in a Zero-Gap CO₂ Electrolyzer

Area of Science:

• Electrochemistry
• Chemical Engineering
• Materials Science

Background:

• Electroreduction of carbon dioxide (CO2RR) is a promising strategy for CO2 emission mitigation and valuable chemical production.
• Conventional flow-field designs in CO2 electrolyzers face challenges with water flooding and salt precipitation, limiting performance.
• Developing efficient and scalable CO2RR technologies is crucial for sustainable chemical synthesis.

Purpose of the Study:

• To design and evaluate a novel flow-field inspired by desert lizards for enhanced CO2RR performance.
• To investigate the impact of the lizard-inspired flow-field on CO partial current density and CO selectivity.
• To demonstrate the effectiveness of this design in preventing water flooding and salt precipitation in zero-gap CO2 electrolyzers.

Main Methods:

• A novel serpentine flow-field design was developed, drawing inspiration from the surface morphology of desert-dwelling lizards.
• The performance of the lizard-inspired flow-field was tested in a zero-gap CO2 electrolyzer using commercial electrocatalysts and membranes.
• CO partial current density and CO selectivity were measured at various current densities and cell sizes.
• Comparative analysis was performed against conventional parallel and serpentine flow-field designs.

Main Results:

• The lizard-inspired flow-field achieved a CO partial current density of 165.5 mA cm-2 at 200 mA cm-2, outperforming conventional designs.
• This novel design effectively prevented both water flooding and salt precipitation without complex modifications.
• At doubled cell size, CO selectivity was 46% and 97% higher than conventional serpentine flow-fields at 350 mA cm-2 and 400 mA cm-2, respectively.
• The technology demonstrated stable and scalable CO2RR using commercially available components.

Conclusions:

• The lizard-inspired flow-field represents a significant advancement in CO2RR technology.
• This innovative design offers a simple yet highly effective method to enhance CO2 electrolyzer performance and stability.
• The technology has the potential to enable a step-change in the scalable and cost-effective utilization of CO2 for chemical production.