Tip‐Encapsulated FeNi ₃ in Wood‐Derived N‐Doped CNTs Arrays for Efficient and Stable AEM Seawater Electrolysis

Abstract

Abstract While anion exchange membrane seawater electrolysis (AEMSE) is a promising green hydrogen generation technology, its industrial implementation remains hindered by the lack of efficient and durable bifunctional electrocatalysts. Here, an innovative electrocatalyst featuring tip‐encapsulated FeNi 3 alloy nanoparticles within N‐doped carbon nanotubes arrays in situ grown on delignified wood carbon (FeNi 3 ‐NCNTs@DWC), integrating tip effect‐induced electron metal‐support interactions (EMSI) with structural advantages of wood‐based carbon is reported. Theoretical and experimental studies demonstrate that the strong EMSI between FeNi 3 alloys and NCNTs@DWC optimizes the interfacial electron configuration and reduces the reaction barrier, thereby enhancing activity and stability. Notably, the dual Cl − ‐repelling layer formed by the tip effect and Ni(Fe)OOH species inhibits Cl − , while selectively adsorbing OH − . Consequently, when integrated into an AEMSE cell, it delivers impressive industrial‐level performance, achieving a cell voltage of 1.88 V at 2.0 A cm − 2 with over 2000 h durability (decay rate <0.0188 mV h −1 ) in alkaline natural seawater. This corresponds to a 98% electrolysis efficiency, an energy consumption of 49.4 kWh kg −1 H 2 , and a record solar‐to‐hydrogen (STH) conversion efficiency of 19.6%. This strategy advances AEMSE toward practical implementation by coupling the tip effect with wood‐derived structural engineering, thereby achieving high activity, selectivity, and long‐term operational stability.