High-valent Mo-triggered lattice oxygen activity in high-entropy LDH enabling ampere-level anion exchange membrane water electrolysis

The sluggish oxygen evolution reaction (OER) hinders efficient water splitting, with conventional adsorbate evolution mechanisms (AEM) facing inherent activity limitations. While the lattice oxygen activation mechanism (LOM) offers a promising pathway for enhanced activity, its practical implementation often grapples with stability issues, especially under industrial-level conditions. Herein, we report a novel ultrathin, bilayer high-entropy MoMnFeCoNiCu LDH nanosheet with a unique graphene-like wrinkled morphology. The strategic introduction of high-valent molybdenum triggers a fundamental shift in the OER mechanism from AEM to LOM, as unequivocally confirmed by in situ Raman spectroscopy and 18 O isotope gas-phase mass spectrometry. This unique Mo-triggered lattice oxygen activity leads to excellent performance: the catalyst achieves a remarkable 235 mV overpotential at 10 mA cm −2 in alkaline media, and maintains 500 h stability at 200 mA cm −2 . Crucially, when integrated into an anion exchange membrane water electrolyzer (AEMWE), our catalyst demonstrates excellent stability by maintaining consistent performance at an unprecedented 1.0 A cm −2 for 200 h, highlighting its immense potential for industrial-scale water electrolysis.