Evidences of 'Through-Plane' Heterogeneities of Aging in a Proton-Exchange Membrane Fuel Cell

摘要

In this study, we investigate "through-plane" heterogeneities of aging of a Pt_3Co/C cathode electrocatalyst aged at I = 20 A or 50 A in a 16 cell proton-exchange membrane fuel cell (PEMFC) stack. Morphological and structural markers of degradation such as the mean nanoparticle size, the degree of agglomeration and the nanostructure of the Pt_3Co/C nanoparticles provide evidence that the electrocatalyst degradation is (i) more pronounced close to the proton-exchange membrane (rationalized by different local/electrochemical environments) and (ii) organized in spatially-localized areas, following the incomplete utilization of the cathode electrocatalyst under the dynamic operation conditions of the PEMFC.