An ultra-low Pt metal nitride electrocatalyst for sustainable seawater hydrogen production

Abstract

The production of hydrogen through electrolysis of seawater is a promising technology for sustainable energy generation. Platinum (Pt) is currently the most efficient catalyst for the hydrogen evolution reaction (HER), but its high cost, scarcity, and poor durability hinder large-scale deployment. Here, we report a highly robust ultra-low Pt (0.07 wt%) electrocatalyst supported on nickel–molybdenum nitride (Pt–Ni@NiMoN) that outperforms commercial 20 wt% Pt/C and previously reported precious and non-precious metal-based electrocatalysts for seawater splitting. This catalyst exhibits an overpotential of only 11 mV at a current density of 10 mA cm⁻² in seawater, and a low overpotential of 90 mV at 500 mA cm⁻², which is required for industrial-scale water splitting. It is also highly durable, maintaining its performance for at least 200 hours in seawater and under harsh conditions of highly chlorinated 2 M NaCl. The Pt–Ni@NiMoN electrocatalyst thus offers a realistic opportunity for large-scale hydrogen production through electrolysis of seawater.