Thermally driven Pt/TiOx interfacial evolution enhances the stability of ultrathin Pt coatings in PEM water electrolyzers

Ultrathin Pt coatings represent a promising strategy for reducing Pt consumption in Ti transport layers for proton exchange membrane water electrolyzers (PEMWE), but their durability is limited by the instability of the Pt/TiO x interface. Herein, a heat-treatment strategy was developed to regulate the Pt/TiO x interface through thermally induced elemental redistribution. Ultrathin Pt coatings were deposited on Ti substrates by magnetron sputtering and heat-treated at different temperatures. Ex-situ characterizations and electrochemical measurements demonstrate that heat treatment significantly enhances the electrochemical stability and durability of the coatings. The modified coating reduces the cell voltage by 35 mV at 2.0 A cm −2 and maintains stable operation for 50 h. Heat treatment promotes Pt, Ti, and O redistribution across the interface, forming a stable interfacial transition region that facilitates electron transport and suppresses coating degradation. This work provides an effective strategy for improving the stability of ultrathin Pt-coated Ti transport layers for PEMWE.