Assessing elevated pressure impact on photoelectrochemical water splitting via multiphysics modeling

Area of Science:

• Materials Science
• Chemical Engineering
• Renewable Energy

Background:

• Photoelectrochemical (PEC) water splitting is a key technology for sustainable hydrogen production.
• Existing research primarily focuses on atmospheric pressure, limiting practical applications requiring high-pressure hydrogen.

Purpose of the Study:

• Investigate the impact of elevated operating pressure on PEC water splitting performance.
• Identify optimal pressure conditions for efficient and practical hydrogen generation.

Main Methods:

• Developed a multiphysics model incorporating empirical data and experimental observations.
• Analyzed the influence of pressure on bubble dynamics, gas crossover, optical losses, and concentration overpotential.

Main Results:

• Elevated pressure significantly affects bubble characteristics, product gas crossover, optical losses, and concentration overpotential.
• An optimal operating pressure range of 6-8 bar was identified for minimizing performance losses.

Conclusions:

• Operating PEC water splitting at elevated pressure is crucial for efficient green hydrogen production.
• The findings offer valuable insights for designing and implementing practical PEC water splitting systems.
• The methodology can be applied to other (photo)electrochemical gas-producing systems.