Fabrication of self-supported catalysts via electrodeposition for proton exchange membrane water electrolysis: Emphasizing on the porous transport layers

The potential of proton exchange membrane water electrolysis (PEMWE) is enormous in tackling worldwide environmental and energy issues in the face of increasing risks associated with climate change and energy scarcity. Nevertheless, the economic competitiveness of hydrogen production is hindered by the challenging operating conditions in acidic environments, resulting in a lower unit cost compared to alternative energy sources. Hence, numerous global research endeavors persist in enhancing the efficiency of essential components in PEMWE systems, specifically the porous transport layer (PTL). Additionally, investigating the interface between catalyst layer (CL) and PTL, which is directly associated with system performance, is imperative for future sustainability and cost reduction. This review focuses on the analysis of fabrication techniques, materials, and structural configurations to enhance the performance of PTLs. Additionally, we suggest the use of self-supported catalysts as potential solutions to enhance mass and charge transfer at the interface between CLs and PTLs, hence facilitating the production of hydrogen on a wide scale. In the last section we provide an overview of the future trajectory and potential of next-generation PEMWE in the context of efficient hydrogen production.