PSI Impuls Award Winner Tobias Schuler

Hydrogen is one of the most promising energy vectors to resolve the problem of anthropogenically induced greenhouse gas emission. Low temperature polymer electrolyte water electrolysis (LT-PEWE) is considered a key technology to produce green hydrogen. The product purity, fast start up and high operational pressure enable an efficient integration of intermittent renewable energies based on hydro, wind and solar.

Tobias Schuler’s PhD thesis entitled ‘Towards a Generic Understanding of Porous Transport Layers in Polymer Electrolyte Water Electrolysis’ focused on obtaining a fundamental understanding of porous transport layers (PTLs) and their impact on cell performance. In addition to the catalyst layer and the ion-conducting membrane, titanium based PTLs are key cell components facilitating fluid, heat and electrical transport as well as providing mechanical cell integrity. Elucidation of underlying electrochemical processes and mechanical interplay were achieved by combination of X-ray tomographic microscopy analysis of PTL microstructure and transport properties as well as in-depth electrochemical analysis. Industrial collaboration with the leading titanium fibre PTL manufacturer SA Bekaert AV (Belgium) enabled the isolation of generic PTL design parameters. The novel insights paved the way to the development of a new class of PTL material based on hierarchically structured titanium sintered particles. Their unique structure promotes higher catalyst utilization as well as improved efficiency. Superior surface properties enabled first time employment of ultrathin membranes boosting cell efficiency. The transformation of fundamental knowledge into industrially relevant applications led to two patent applications and the establishment of PSI’s PTL materials NovElyTi^TM which are currently under consideration by industrial PEWE manufacturers.