A metal surface that becomes more active as it changes could help green hydrogen electrolyzers run harder and longer.
Researchers at the Chinese Academy of Sciences have developed an electrode that combines five metals in a high-entropy antiperovskite structure. Supported on porous nickel foam, the material helped an anion exchange membrane (AEM) electrolyzer sustain industrially relevant current densities for hundreds of hours with little loss of performance.
The work, led by Guowen Meng and Bin Chen of the Institute of Solid State Physics at the Hefei Institutes of Physical Science, was published in ACS Nano.
Removing a Hydrogen Production Bottleneck
Electrolysis uses electricity to split water into hydrogen and oxygen. When that electricity comes from renewable sources such as solar or wind power, the resulting hydrogen can be produced without the direct carbon emissions associated with conventional methods that rely on fossil fuels.
AEM water electrolysis aims to combine the lower material costs of alkaline electrolyzers with some of the performance advantages of proton exchange membrane systems. One persistent obstacle is the oxygen evolution reaction (OER), a complex process that transfers four electrons and typically proceeds much more slowly than hydrogen formation.
Accelerating this reaction requires highly active catalysts, but intense operating conditions can gradually dissolve, restructure, or deactivate them. Commercially practical electrodes must therefore deliver strong performance at high current densities while remaining stable for extended periods.
Five Metals Form One Electrode
The researchers created a high-entropy antiperovskite material with the composition (InN(NiCoFeCrV)₃), bringing nickel, cobalt, iron, chromium, and vanadium together within a single structure. Combining several metals can produce electronic and chemical interactions that are unavailable in simpler materials, allowing researchers to tune catalytic activity and durability.
Rather than applying the catalyst as a separate coating, the team grew it directly on nickel foam. The foam provides a conductive, porous framework with abundant exposed surface area, helping electricity and electrolyte reach the catalytic material efficiently.
“Our goal was to develop a durable and efficient electrode for large-scale hydrogen production,” said Guowen Meng. “This electrode showed excellent oxygen evolution performance and long-term stability in AEM water electrolysis, demonstrating its potential for practical hydrogen production.”
A Surface That Rebuilds Itself
In an alkaline electrolyte, the electrode required an overpotential of only 279 millivolts to reach 100 milliamperes per square centimeter. It continued operating for more than 500 hours, indicating that its activity could withstand prolonged exposure to demanding reaction conditions.
When installed in an AEM electrolyzer, the electrode delivered 500 milliamperes per square centimeter at a cell voltage of 1.662 volts. The device remained stable for more than 400 hours with little deterioration, an important result because large-scale hydrogen systems must operate at high output without frequent catalyst replacement.
Analysis revealed that the electrode did not remain chemically static. Some of its metal components gradually dissolved during operation, allowing a new active layer to develop at the surface. Instead of simply degrading the catalyst, this reconstruction created favorable interactions between the surface and the underlying antiperovskite material, improving charge transfer and oxygen evolution activity.
Toward More Affordable Green Hydrogen
The findings suggest that controlled surface reconstruction can be treated as a design feature rather than an unavoidable form of catalyst damage. By engineering the original material to transform into a highly active surface while retaining a stable foundation, researchers may be able to extend electrode life without relying heavily on scarce precious metals.
This approach offers a potential route to durable, lower-cost electrodes for AEM water electrolysis. Further testing under industrial conditions will be needed, but the combination of high current output, sustained operation, and a self-formed active surface could support more efficient production of green hydrogen.
Reference: “Defect-Driven Surface Reconstruction in High-Entropy Antiperovskite to Generate Mott–Schottky Interface for Boosting Oxygen Evolution” by Jing Zhang, Rui Wan, Yuguang Wang, Xiaoxiao Wu, He Liu, Bin Chen and Guowen Meng, 29 June 2026, ACS Nano.
DOI: 10.1021/acsnano.6c02462
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