Nickel–Antimony Electrocatalyst for Durable Acidic Hydrogen Evolution Reaction in Proton Exchange Membrane Electrolyzers

Developing a nonprecious alternative to platinum as hydrogen
evolution
reaction (HER) catalyst in a proton exchange membrane water electrolyzer
(PEM-WE) has been a long-standing pursuit in electrochemical water
splitting. Here, we report the theory-aided discovery of a noble-metal-free
NiSb electrocatalyst with high stability and activity for acidic HER,
continuously operating over 3000 h at 2 A cm–2 and
60 °C with a cell voltage of 2.28 V in the PEM-WE. This NiSb
catalyst was identified through a comprehensive stability and activity
evaluation framework with computations, incorporating rigorous aqueous
stability assessment via Pourbaix diagram analysis. Further experimental
studies confirmed the successful synthesis of NiSb and impressive
performance for acidic HER, verifying the computational predictions.
The record-high durability, high activity, and low cost make NiSb
a promising alternative to Pt for practical application in PEM-WE.