High-performance gas diffusion electrodes for next-generation CO₂ conversion technologies

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• Electrochemical CO2 reduction (eCO2R) is a promising CO2 utilization technology.
• Current eCO2R processes face limitations in industrially relevant product formation rates.
• Gas diffusion electrodes (GDEs) are critical components in eCO2R, with their structure significantly impacting performance.

Purpose of the Study:

• To review recent advancements in GDE structural design and materials for eCO2R.
• To explore the structure-performance relationship in GDEs for eCO2R.
• To identify current challenges and future research directions for industrial eCO2R.

Main Methods:

• Review of recent literature on GDEs for eCO2R.
• Analysis of structure-performance relationships in various GDE designs.
• Discussion of catalyst, gas diffusion structure, electrolyte, and interface optimization.

Main Results:

• Transition from planar GDEs to hollow fiber GDEs (HFGDEs) and advanced planar designs (mesh, woven, carbon-free, heteroarchitectural).
• Improved triple-phase boundary formation and mass transfer in advanced GDEs.
• Achieved high current densities (~3 A cm-2), high faradaic efficiencies, and extended stability (>100 h).

Conclusions:

• Optimized GDE design and materials are key to overcoming eCO2R limitations.
• Advanced GDEs show potential for industrially viable CO2 utilization.
• Further research is needed to address bottlenecks and facilitate practical implementation of GDE-based eCO2R systems.