Bio-derived porogens architecting sintered-titanium porous transport layers for performance-enhanced PEM water electrolysis

The porous transport layer (PTL) is a crucial component in proton exchange membrane water electrolyzer (PEMWE), facilitating the transport of liquid/gas two-phase fluid to the catalyst layer and the conduction of electrons to the bipolar plate. Currently, conventional PTL manufacturing processes suffer from the high cost of raw materials such as organic pore-formers and solvents, and usually generate environmentally harmful emissions and liquid waste. In this work, we explored the use of biomass pore-formers—potato starch, wheat starch, corn starch and rice starch—in the fabrication of PTLs. The research examined the impact of pore former type on the pore structure of the PTLs, revealing potato starch to be highly effective in controlling this structure. The pore structure can be further optimized by modifying the titanium (Ti) powder to potato starch ratio in the aqueous slurries. Additionally, the influence of various biomass pore-formers and their concentrations on the performance of PEMWEs was investigated. The PTLs produced with potato starch pore-formers exhibited 1.84 V at 2 A cm −2 and 120 mV decrease in cell voltage at a current density of 4 A cm −2 compared to commercial Ti PTLs, showcasing the potential of biomass pore formers for enhancing the efficiency of metal-based PTLs in PEMWEs and other energy conversion and storage systems.