Materials for proton exchange membrane fuel cells and electrolyzers: combining SEM imaging, Raman spectroscopy and other experimental methods

Licentiate thesis, 2026

The global transition toward a decarbonized energy infrastructure requires robust energy storage solutions to balance intermittent renewable power. When paired, polymer electrolyte membrane (PEM) electrolyzers and fuel cells offer an effective mechanism for the generation, and utilization of green hydrogen. However, optimizing these devices requires a profound understanding of their complex, multi-phase porous transport media. A persistent challenge in materials science is decoupling the intricate chemical and structural interactions within these components on a micro-scale.

In this work, identical location (IL) methodologies are developed and applied to bridge the gap between macroscopic electrochemical performance and localized microscopic phenomena. By coupling scanning electron microscopy (SEM) with chemical spectroscopy (EDX and confocal Raman) and tracking identical material locations before assembly and after disassembly, individual component behaviors can be isolated. For fuel cell gas diffusion layers (GDLs), co-located Raman mapping and SEM/EDX imaging showsthat the base carbon architecture and presence of a binder substantially controls the spatial distribution of hydrophobic polymer treatments in the studied samples. For electrolyzer porous transport electrodes (PTEs), IL imaging verifies the mechanical survivability of novel, high surface-area platinized carbon nanofiber scaffolds even after extended operation. Furthermore, Raman analysis of the imprints left by such rigid PTEs on the proton exchange membrane (PEM) highlights how non-uniform interfacial contact drives localized chemical degradation. This thesis seeks to combine such methods to provide a better understanding of the materials and interfaces in PEM fuel cells and electrolyzers.