Triple-Layer Porous Transport Layers with Ultra-High Porosity for Enhanced Oxygen Transport and Catalyst Utilization...

The commercialization of proton exchange membrane water electrolysis (PEMWE) for green hydrogen production hinges on the development of low-cost, high-performance titanium porous transport layers (PTLs). This study introduces a triple-layer Ti-PTL with a graded porous structure and a 75% ultra-high porosity backing layer, fabricated through tape casting and roll calendering. This triple-layer PTL, composed of a microporous layer, an interlayer, and a highly porous backing layer, enhances catalyst utilization, mechanical integrity, and mass transport. Digital twin technology using X-ray revealed increased contact area and triple-phase boundary at the interface with the catalyst layer, significantly improving oxygen evolution reaction kinetics. Numerical simulations demonstrated that the strategically designed porous structure of the triple-layer PTL facilitates efficient oxygen transport, mitigates oxygen accumulation, and improves reactant accessibility. Electrochemical evaluations showed improved performance, achieving 127 mV reduction in voltage at 2 A cm^-2 compared to a commercial PTL, highlighting its potential to enhance PEMWE efficiency and cost-effectiveness.