• • The HVI Metal-CoMoO4/NF catalyst achieves an overpotential of only 307 mV at 100 mA cm−2 in 1.0 M KOH, outperforming conventional cobalt-based spinels and approaching noble metal benchmarks, which is critical for reducing energy losses in industrial water electrolysis.
• • A Tafel slope of 63.13 mV dec−1 indicates favorable reaction kinetics, enabling higher current densities at lower applied voltages, thereby improving overall system efficiency for hydrogen production.
• • The catalyst maintains stable operation for over 320 hours at high current density, demonstrating exceptional durability that addresses the structural instability commonly observed in spinel OER catalysts, a key requirement for long-term commercial deployment.
• • In situ ATR-FTIR, Raman, and XRD analyses reveal a structure-guided dynamic self-reconstruction into a well-crystallized cobalt (oxy)hydroxide phase, which serves as the true active phase, providing a mechanistic blueprint for designing adaptive electrocatalysts with enhanced activity and stability.