High-entropy Electrode Improves Efficiency of Green Hydrogen Production

Water electrolysis uses renewable electricity to produce clean hydrogen. Among various technologies, anion-exchange membrane (AEM) water electrolysis combines the advantages of alkaline systems and proton-exchange membrane systems. However, its large-scale application is limited by slow oxygen evolution reaction and the need for catalysts with high activity and long-term stability.

In a study published in ACS Nano, a team led by Prof. MENG Guowen and Prof. CHEN Bin from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences developed a high-entropy antiperovskite electrode (InN(NiCoFeCrV)3) supported by nickel foam for efficient AEM water electrolysis, improving the efficiency and durability of hydrogen production.

Researchers designed a high-entropy antiperovskite electrode containing five metal elements: nickel, cobalt, iron, chromium, and vanadium, which are grown directly on nickel foam. The unique structure helps maintain catalytic activity while promoting the formation of active sites during operation.

"Our goal is to develop a durable and efficient electrode for large-scale hydrogen production," said Prof. MENG, "This electrode showed excellent oxygen evolution performance and long-term stability in AEM water electrolysis, demonstrating its potential for practical hydrogen production."

Tests showed that the electrode required an overpotential of only 279 mV to reach a current density of 100 mA cm-2 and remained stable for more than 500 hours in alkaline electrolyte. When used in an AEM electrolyzer, it delivered 500 mA cm-2 at a cell voltage of 1.662 V and maintained stable operation for over 400 hours with little performance loss.

Furthermore, researchers showed that some metal elements gradually dissolved during operation, leading to the formation of an active surface layer. The interaction between the surface layer and the underlying material improved charge transfer and enhanced catalytic performance.

The study provides a new strategy for designing durable, low-cost electrodes for AEM water electrolysis, and supports the development of more efficient green hydrogen technologies.