From combinatorial explosion to targeted optimization: a hybrid strategy for high-entropy catalyst discovery

• • Hybrid screening reduces search space from >10^10 to 13 candidate systems, enabling practical experimental validation within a single study. • • Optimal HEO composition Fe17.57Co28.45Ni31.27Mo10.57Zr12.14 achieves an OER overpotential of 240 mV at 10 mA cm−2, outperforming benchmark IrO2 (typically >300 mV) under identical conditions. • • Catalyst sustains 1 A cm−2 for >600 h in 1 M KOH with negligible degradation, demonstrating industrial-scale durability for alkaline water electrolysis. • • Mechanistic insight: Mo modulates adsorption of oxygen intermediates (e.g., *OH, *O) via electronic tuning, while Zr enhances structural stability, providing a design rule for future multi-element catalysts.