Under CopyrightZamel, NadaNadaZamelBhattarai, ArjunArjunBhattaraiGerteisen, DietmarDietmarGerteisenGroos, UlfUlfGroosHebling, ChristopherChristopherHebling2022-03-1216.8.20142015https://publica.fraunhofer.de/handle/publica/38801710.24406/publica-fhg-388017In this work, we use the polarization curve of a polymer electrolyte membrane (PEM) fuel cell to investigate the inter-connected transport processes in its electrodes. The investigation is based on a segmented (7 by 7) PEM fuel cell. A local N-shaped negative differential resistance (N-NDR) branch was measured in the steady state polarization curve of the cell near its oxygen outlet. This phenomenon was also observed in a much more pronounced manner for highly-transient polarization curves on all segments. In this study, we show that even despite the cell running under normal conditions, in the case of oxygen starvation, a hydrogen evolution takes place in the cathode catalyst layer. This theory is illustrated through experimental measurements.enEnergietechnikWasserstoff- und BrennstoffzellentechnologieBrennstoffzellensystemevolution reactionnegative differential resistancepolarization curveoxygen depletion621697conference paper