In this study, we aim to apply a correlative combination of holographic tomography, x-ray fluorescence computed tomography and 2D-XRF with a nanoprobe to obtain key insights into durability issues of Fe-based fuel cell catalyst materials. Fe-leaching from the C-encapsulated iron nanoparticles present in the initial catalyst as well as concomitant-poisoning of the catalyst layer's H+-conducting ionomer with leached Fe-ions are both possible mechanisms to which instability issues are ascribed. The unique combination of x-ray techniques above, correlatively applied to a pristine and degraded sample allow us to resolve structural integrity and material distribution (holography) of both catalysts together with elemental distributions mapped on top of the morphology (fluorescence). The results, in combination, will provide insights on both possible degradation mechanisms.