Synergistic Teamwork of Non-Noble Metals: The Design of Active and Robust Intermetallic Compounds for Hydrogen Evolution Reaction in Industrial Alkaline Water Electrolysis

In this work, we have demonstrated a double-boosting strategy that can significantly enhance the stability of hydrogen evolution reaction (HER) for non-noble-metal-based electrocatalysts operating in harsh industrial conditions (6.0 M KOH, 343 K). With the incorporation of early-transition-metal and main-group elements in Ni metal, ternary TiAlNi₂ and TiNi₂Sn both exhibit higher robust durability for HER than binary AlNi and metal Ni due to the strong bonding states of Ti-Ni and Al/Sn-Ni below the Fermi level. Additionally, they display remarkable HER efficiency, for which only overpotentials of ca. -22 and -67 mV are required for TiAlNi₂ and TiNi₂Sn to reach a current density of 10 mA/cm² (η₁₀) in 1.0 M KOH. Theoretical calculation revealed that their outstanding HER activities (outperforming commercial Pt/C, Pt = 5 wt %, η₁₀ = -76 mV) can be attributed to a synergistic teamwork among Ti, Ni, and Al/Sn elements. The overpotentials at 500 mA/cm² of TiAlNi₂ and TiNi₂Sn are much smaller than that of commercial Ni foam. More importantly, they show steady HER performances over a period of 400 h at a high current density (400 mA/cm²) in harsh industrial conditions.