Large-Scale, Low-Cost, and High-Efficiency Water-Splitting System for Clean H₂ Generation

Area of Science:

• Electrochemistry
• Materials Science
• Renewable Energy

Background:

• Electrochemical water splitting is crucial for the hydrogen economy.
• Noble metal catalysts are expensive and scarce.
• Scalable synthesis and practical device design for hydrogen generation remain challenges.

Purpose of the Study:

• To design and demonstrate a scalable alkaline water-splitting electrolyzer system.
• To utilize earth-abundant catalysts for efficient hydrogen and oxygen evolution.
• To address challenges in catalyst synthesis on current collectors and practical device design.

Main Methods:

• Developed a modular alkaline water-splitting electrolyzer.
• Employed scaled-up metal foam electrodes coated with NiMo alloy and Ni₃Fe oxide.
• Integrated an electrolyte circulation system for enhanced mass transport.

Main Results:

• Achieved efficient hydrogen evolution (HER) and oxygen evolution (OER) using low-cost catalysts.
• Demonstrated a 10 × 10 cm² unit cell with an onset voltage of 1.54 V.
• Delivered practical currents of 20 A and 55 A, yielding 9.1 and 25.0 L/h H₂, respectively, without iR compensation.

Conclusions:

• The designed electrolyzer system offers a scalable and efficient approach for hydrogen production.
• The use of earth-abundant catalysts and modular design promotes practical applications in the hydrogen economy.
• This work encourages further research into practical device engineering for large-scale water splitting.