Triangular-ordered Co atoms activate substrates for ampere-level durable hydrogen production.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Alkaline anion exchange membrane (AEM) electrolyzers face durability challenges for catalysts under harsh operating conditions like high current densities.
• Atomically dispersed catalysts are particularly vulnerable due to weak interactions, limiting their long-term stability.

Purpose of the Study:

• To develop an atom-ordering strategy for fabricating durable catalysts for AEM electrolyzers.
• To enhance the stability and activity of catalysts under industrial operating conditions.

Main Methods:

• Fabrication of cobalt (Co) triangular orders within a vanadium nitride (VN) lattice using a photo-induced self-assembly method.
• Characterization of catalyst structure and performance in AEM water electrolyzers.

Main Results:

• Co atoms thermodynamically favor triangular arrangements in the VN lattice, creating an atom-ordered catalyst.
• The Co-triangular order activates adjacent V atoms, leading to efficient hydrogen production at high current densities (> 1 A cm⁻²).
• The catalyst demonstrated stable performance at 1 A cm⁻² and an AEM water electrolyzer achieved 1.97 V with long-term durability.

Conclusions:

• Atom ordering provides a viable strategy for designing catalysts that balance high activity and long-term stability for AEM electrolyzers.
• The developed catalyst design is suitable for industrial hydrogen production applications demanding robust performance.