یک بررسی ترکیبی در محل و پس از مرگ در مورد تخریب دائمی محلی در یک سلول سوختی متانول مستقیم

This work proposes a systematic experimental investigation, coupling in-situ diagnostics (electrochemical and mass transport investigation) with ex-situ analyses of pristine, activated and aged components (X-ray photoelectron spectroscopy and transmission electron microscopy), with an in-plane and through-plane local resolution. Such a combined approach allows to identify on one hand the degradation mechanisms, the affected components and the presence of heterogeneities; on the other hand, it allows to quantify the effect of the major mechanisms on performance decay. Thanks to a novel procedure, temporary (21 μV h−1) and permanent degradation (59 μV h−1) are separated, distinguishing the latter in different contributions: the effects of active area loss at both at anode (9 μV h−1) and cathode (31 μV h−1), mass transport issue (15 μV h−1) and membrane decay (4 μV h−1). The post-mortem analysis highlights the effect of degradation mechanisms consistent with the in-situ analysis and reveals the presence of considerable in plane and through plane heterogeneities in: particle size growth in catalyst layers, Pt/Ru and polymer content in catalyst and diffusion layers, Pt/Ru precipitates in the membrane.