Descriptor-Driven Designed FeCoNiMoV High-Entropy Alloys for Exceptional Oxygen Evolution Activity

The oxygen evolution reaction (OER) generally relies on scarce noble electrocatalysts with low activity and stability. High-entropy alloys (HEAs) offer compositional flexibility to overcome these limitations; however, rational design principles and scalable synthesis methods are still lacking. Herein, we propose a strategy with descriptor-guided screening and core-shell metal-organic framework pyrolysis for developing FeCoNi-based HEA catalysts. The obtained FeCoNiMoV HEA catalysts achieve an exceptionally low overpotential in alkaline media (212 mV at 10 mA/cm²), with an ultralow Tafel slope (41.33 mV/dec) and excellent long-term stability. Our theoretical-experimental-combined scheme further reveals that the preferential trace leaching of V/Mo from FeCoNiMoV triggers the surface reconstruction, leading to the formation of active high-valence Ni/Co species and enabling dual-pathway activation. Our study not only reveals the catalytic mechanism of HEAs in the OER but also establishes a universal design framework for accelerating the development of HEA catalysts.