Advancing green hydrogen production: Technological and economic perspectives on saltwater electrolysis

Abstract

Saline water electrolysis provides a sustainable route for hydrogen production by directly utilizing saltwater without desalination. We report a custom-built electrolyzer employing a corrosion-resistant hierarchical titanium anode coated with RuO₂–IrO₂ and a Ni–SS cathode. The oxygen-selective anode effectively suppressed chlorine evolution in chloride-rich media, enabling stable operation. Electrolysis of 3 % NaCl solution produced 140.7 mmol h⁻¹ hydrogen at 17.89 mA cm⁻² in a 1-L reactor, with cell performance strongly dependent on salinity and current density. Continuous operation for 72 h under 5 V demonstrated durability, while optimization algorithms improved system efficiency. These results highlight the potential of saline water electrolysis as a scalable pathway for green hydrogen generation.