Enhancing durability of Pt-coated titanium porous transport layers for PEM water electrolysis using TiN interlayers

Abstract

The durability and efficiency of proton exchange membrane water electrolysers (PEMWEs) are influenced by multiple factors, particularly the stability of platinum (Pt) coated porous transport layers (PTLs), which degrade under acidic and oxidative environments. TiO_x passivation during anodic polarization increases interfacial resistance and reduces electrochemical performance. To address this issue, this study explores the use of a titanium nitride (TiN) interlayer, deposited via reactive magnetron sputtering, to enhance the stability of Pt-coated titanium felt (Ti-felt) PTLs. Pt layers are deposited by varying sputtering power, and TiN interlayers with varying thickness are applied beneath the best-performing Pt layer. Electrochemical corrosion testing, long-term chronoamperometry (1 A cm⁻² in 0.5 M H₂SO₄), and in situ PEMWE single-cell evaluations show that the sample with the 400 nm TiN interlayer exhibits the lowest corrosion current (39.26 µA cm⁻²), improved charge transfer resistance (3552 Ω cm²), and structural integrity. Additionally, the TiN interlayer extended the Pt-coated PTL durability by 80 hours, significantly reducing interfacial degradation and offering a promising strategy for long-lasting high-efficiency PEMWE systems.