High-performance alkaline water electrolyzers based on Ru-perturbed Cu nanoplatelets cathode

Area of Science:

• Electrochemistry
• Materials Science
• Renewable Energy

Background:

• Conventional alkaline electrolyzers are limited to low current densities (<0.5 A/cm²).
• High capital and operational expenditures hinder widespread adoption for high-throughput hydrogen production.
• Scarcity of platinum-group metals presents a challenge for electrolyzer catalyst development.

Purpose of the Study:

• To design a cost-effective and robust cathode for alkaline electrolyzers.
• To achieve high current densities and stable operation in alkaline electrolysis.
• To reduce the overall production cost of hydrogen.

Main Methods:

• Electrodeposition of ruthenium (Ru) nanoparticles on vertically oriented copper (Cu) nanoplatelet arrays on metallic meshes for the cathode.
• Coupling the novel cathode with an anode based on stacked stainless steel meshes.
• Testing electrolyzer performance at various current densities and voltages, and assessing long-term stability.

Main Results:

• Achieved high current densities of 1 A/cm² at 1.69 V and 3.6 A/cm² at 2 V, comparable to proton-exchange membrane electrolyzers.
• Demonstrated stable operation in continuous (1 A/cm² for >300 h) and intermittent modes.
• Projected a hydrogen production cost of US$2.09/kg for a 1 MW plant, meeting global targets.

Conclusions:

• The developed electrode technology, utilizing a small amount of ruthenium, offers a promising solution for high-throughput alkaline electrolysis.
• This approach addresses the cost and operational expenditure challenges of conventional alkaline electrolyzers.
• The technology provides a viable alternative to scarce platinum-group metals, enabling cost-effective hydrogen production.