Colloid‐Mediated Synthesis of Hierarchically Porous Amorphous Catalyst for Durable Industrial‐Scale Water Electrolysis

Efficient and scalable hydrogen production via water electrolysis requires electrode architectures that combine high catalytic activity, effective active-site utilization, and mechanical durability at industrial current densities. However, conventional synthesis routes often produce dense, fragile catalyst layers that limit performance and scalability. Herein, a colloid-mediated electroless plating (CMEP) strategy is reported for the facile fabrication of hierarchically porous, amorphous Fe-NiWB electrodes under ambient conditions. During CMEP, the in situ generation of Fe-W-O colloids suppresses compact layer growth, yielding an open architecture with abundant accessible sites, accelerated mass transfer, and strong substrate anchoring. Comprehensive structural and electronic analyses reveal that Fe incorporation modulates the local coordination environment, enhances intrinsic activity, and promotes beneficial dynamic surface reconstruction under alkaline oxygen evolution reaction (OER) conditions. The resulting electrode delivers excellent bifunctional activity and stability, sustaining 500 mA cm^-2 for over 2000 h with negligible degradation in both hydrogen and oxygen evolution reactions (HER/OER). When integrated into an anion exchange membrane (AEM) electrolyzer, it delivers 500 mA cm^-2 at 1.55 V with remarkable long-term durability. A preliminary techno-economic analysis (TEA) highlights the scalability and cost competitiveness of this approach, underscoring its promise for economically viable large-scale green hydrogen production.