Résumé
Energy storage and conversion occur through the manipulation of molecular bonds, catalyzed at electrified interfaces between an ion conductor and an electrocatalyst material within electrochemical reactors like hydrogen fuel cells or water electrolysers. Nanostructured electrode materials are essential for minimizing energy losses and maximizing atom efficiency in these reactions. They provide significant advantages in atomic dispersion, leading to enhanced energy efficiency and performance benefits.The rapid and efficient development of new nanostructured catalysts requires in-depth knowledge of the relationships between nanostructure and their electrocatalytic performance and stability. Such relationships appear of utmost importance for the scientific community.In this presentation, I will highlight some structure-activity-stability relationships of non-platinum group metal (PGM) nanostructured catalysts in acid and alkaline media. Examples will be devoted to elucidating the degradation mechanisms of iron-nitrogen-carbon (Fe-N-C) materials during fuel cell operation. Various conditions were investigated, including potential range, gas atmosphere, electrolyte, and temperature [1]. Several ex situ and in situ physicochemical techniques were combined to differentiate possible degradation mechanisms. Specifically, the combination of inductively coupled plasma mass spectrometry measurements with a gas diffusion electrode and microkinetic models showed a positive correlation between the metal dissolution profile and the local pH variation in the catalyst layer of Fe-N-C [2]