Dealloying-Induced Zeolite-like Metal Framework of AB₂ Laves Phase Intermetallic Electrocatalysts

Exploring an efficient and robust electrocatalyst for hydrogen evolution reaction (HER) at high pH and temperature holds the key to the industrial application of alkaline water electrolysis (AWE). Herein, we design an open tunnel structure by dealloying a series of Laves phase intermetallics, i.e., MCo₂ and MRu_0.25Co_1.75 (M = Sc and Zr). The dealloying process can induce a zeolite-like metal framework for ScCo₂ and ScRu_0.25Co_1.75 by stripping Sc metal from the center of a tunnel structure. This structural engineering significantly lowers their overpotentials at a current density of 500 mA/cm² (η₅₀₀) ca. 80 mV in 1.0 M KOH. Through a simple process, ScRu_0.25Co_1.75 can be easily decorated on a carbon cloth substrate and only requires 132 mV to reach 500 mA/cm². More importantly it can maintain activity over 1000 h in industrial conditions (6.0 M KOH at 333 K), showing its potential for practical industrial applications.