Wide proliferation of low temperature hydrogen fuel cell systems, a key part of the hydrogen economy, is hindered by degradation of the platinum cathode catalyst. Here, we provide a device level assessment of the molecular scale catalyst degradation phenomena, using advanced operando X-ray scattering tomography tailored for device-scale imaging. Each cell component, including the catalyst, carbon support, polymer electrolyte, and liquid water can be simultaneously mapped, allowing for deep correlative analysis. Chemical and thermal gradients formed inside the operating fuel cell produce highly heterogeneous degradation of the catalyst nanostructure, which can be linked to the macroscale design of the flow field and water distribution in the cell materials. Striking differences in catalyst degradation are observed between operating fuel cell devices and the liquid cell routinely used for catalyst stability studies, highlighting the rarely studied but crucial impact of the complex operating environment on the catalyst degradation phenomena. This degradation knowledge gap highlights the necessity of multimodal in situ characterization of real devices when assessing the performance and durability of electrocatalysts.
@article{arxiv.2008.04770,
title = {Holistic Multi-scale Imaging of Oxygen Reduction Reaction Catalyst Degradation in Operational Fuel Cells},
author = {Isaac Martens and Antonis Vamvakeros and Nicolas Martinez and Raphaël Chattot and Janne Pusa and Maria Valeria Blanco and Elizabeth A. Fisher and Tristan Asset and Sylvie Escribano and Fabrice Micoud and Tim Starr and Alan Coelho and Veijo Honkimäki and Dan Bizzotto and David P. Wilkinson and Simon D. M. Jacques and Frédéric Maillard and Laetitia Dubau and Sandrine Lyonnard and Arnaud Morin and Jakub Drnec},
journal= {arXiv preprint arXiv:2008.04770},
year = {2020}
}