Additively manufactured porosity-graded membrane electrode assemblies (AM-MEA)

• Applicants: Dr. Volker Brüser; Dr.-Ing. Jörg Hermsdorf
• Subject Area: Coating and Surface Technology ; Materials in Sintering Processes and Generative Manufacturing Processes ; Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 575510032

Green hydrogen, produced from regenerative sources, is crucial for global energy transition and defossilization efforts. Efficient electrolyzers are essential for hydrogen production, necessitating innovative engineering approaches to optimize porous transport layers (PTL) and catalyst layers. Additive manufacturing (AM) offers the flexibility to enhance diffusion and minimize ohmic losses by controlling pore size distribution in the PTL while conserving material resources. By combining a catalyst-coated PTL with a full-coverage catalyst layer, a three-phase boundary is achieved during hotpressing with the membrane, promoting the diffusion of protons, oxygen, and water. This approach exhibits superior degradation properties and low contact resistance due to robust metallic bondings formed during catalyst-on-substrate deposition. Furthermore, utilizing a self-supported structure with high electrochemical activity and low loading for the catalyst layer introduces a novel aspect compared to conventional particle catalysts found in catalyst-coated membranes. In a collaborative effort new production methods for membrane electrode assemblies (MEAs) through laser-based additive manufacturing are explored. The project also aims to optimise polymer electrolyte membrane (PEM) electrolysis by studying the mechanical and material properties, as well as the physical vapour deposition processes, for electrocatalytic applications. The project will develop an innovative approach to PEM water electrolysis, utilising a graded, 3D-printed porous transport layer (PTL) combined with a highly porous, self-supporting catalyst layer. The focus lies in understanding the interface between these components to enable efficient reactant transport and electrochemical reactions. The project also explores a sequential process involving sputtering methods to deposit a nanoporous catalyst layer on the PTL. The objectives include investigating the relationship between mass transfer and PTL porosity, optimizing process parameters for additive manufacturing, refining metallic surfaces, and achieving high catalytic activity with low catalyst mass. Critical research questions pertain to optimizing conductivity, creating an optimal balance between porosity and mechanical stability, and determining the limitations of the material and the process. Two main objectives are (a) production of 3D-graded PTLs with a porosity between 40 and 60 % and an average pore diameter between 5 and 200 µm with a maximum standard deviation of 15 %, (b) a 33 % higher current density (4 A cm-2 at 2 V) compared to currently commercially available MEAs while reducing Ir loading in the single-cell electrolyzer.

• DFG Programme: Research Grants