3D transition metal boride monolithic electrode for industrial hectoampere-level current anion exchange membrane water electrolysis

Abstract

High performance, cost-efficient anion exchange membrane water electrolysis (AEMWE) is of great current interest for industrial-level hydrogen production. However, the lack of active and robust catalytic electrode severely impedes the development of this technology. Herein, a versatile strategy of 3D hierarchical porous monolithic electrode enabling industrial hectoampere-level current AEMWE is successfully explored for the first time. By a facile electroless plating technique coupled with corrosion engineering process, a series of low-cost and highly active 3D transition metal boride (etched-TMB, TM=Ni, Co, NiP, NiMo, CoP, CoMo, CoNi) catalytic electrodes have been prepared. A distinctive hierarchically structured etched-NiPB@MS alloy monolithic electrode exhibits a superior bifunctional hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalytic activity and large-current stability, which derive from enhanced intrinsic activity, sufficient electrochemical active sites, mechanical stability as well as efficient gas/liquid transport pathways. An AEMWE electrolyzer with 10$\times$10 cm² etched-NiPB@MS as both anode and cathode works efficiently at large current of 100 A (1 A cm⁻²) and reaches a H₂ production rate of 41.78 L h⁻¹, verifying its huge potential for industrial hydrogen production. This study paves out a new approach for high-efficient catalytic electrode and industrial-level current AEMWE.