High-entropy antiperovskite catalyst turns surface wear into a performance boost

In the production of green hydrogen via anion exchange membrane (AEM) electrolysis, the oxygen evolution reaction (OER) acts as the primary bottleneck. While hydrogen release is relatively fast, the OER requires the transfer of four electrons, making it slower and more energy-intensive. To overcome this, catalysts must maintain high current densities without dissolving in harsh alkaline environments—a requirement that typically leads to rapid material degradation. Researchers from the Institute of Solid State Physics at the Chinese Academy of Sciences have challenged the assumption that surface wear is an inevitable failure. By utilizing a high-entropy antiperovskite material with the formula InN(NiCoFeCrV)₃, the team integrated five metals—nickel, cobalt, iron, chromium, and vanadium—grown directly onto a porous nickel scaffold. This structure maximizes electrolyte access to active sites, but the real shift occurs during operation. The study identifies a distinction between destructive wear and functional reconstruction. As the catalyst operates, certain metals gradually leach from the surface. Instead of collapsing, the material undergoes a structural reorganization that forms a Mott-Schottky interface. This transformation effectively refreshes the electrode's working zone, improving charge transfer and increasing activity over time.