Gas Evolution in Water Electrolysis

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• Gas bubbles generated during water electrolysis (hydrogen evolution reaction and oxygen evolution reaction) significantly affect energy conversion efficiency.
• Understanding gas bubble-electrode interactions is crucial for optimizing hydrogen production.

Purpose of the Study:

• To survey current knowledge on gas bubble-electrode interactions and their impact on water electrolysis devices.
• To outline bubble life cycle processes, characterization techniques, and electrode tailoring for gas removal.
• To review modeling efforts for individual bubbles and multiphase flows.

Main Methods:

• Literature review of gas evolution phenomena in water electrolysis.
• Analysis of physical processes in bubble life cycles.
• Summary of in situ and practical device characterization techniques.
• Discussion of electrode design strategies for gas removal.
• Review of computational fluid dynamics and multiphase flow modeling.

Main Results:

• Gas bubble dynamics at electrode surfaces are complex and influence overall device performance.
• Tailoring electrode surfaces can enhance gas removal, especially at high current densities.
• Current modeling approaches provide insights into bubble behavior and multiphase flow.

Conclusions:

• Further research is needed to fully understand gas evolution in electrochemical devices.
• Improved simulations of multiphase flows are essential for advancing hydrogen production technology.
• Addressing outstanding questions in gas evolution characterization and modeling will enhance energy conversion efficiency.