20.500.12556/RUL-181975 Flow-field effect on reformate gas tolerance in post-doped HT-PEMFC High-temperature proton exchange membrane fuel cells (HT-PEMFCs) are attractive for integration with methanol steam reforming, but reformate impurities strongly affect electrochemical kinetics and spatial current distribution. This study combines polarization analysis, electrochemical impedance spectroscopy (EIS) with distribution of relaxation times (DRT), and segmented current measurements to investigate degradation under CO▫$_2$▫-CO reformate conditions. The results reveal clear flow-field-dependent mechanisms: serpentine channels show stronger low-frequency DRT contributions linked to cumulative gas-transport limitations, while parallel channels exhibit higher transport peaks but lower spatial poisoning severity. At elevated CO concentrations, voltage losses in the parallel configuration exceed those of the serpentine by ∼15%, with a ∼1.7 × increase in the fast DRT process contribution. Spatial analysis shows channel-governed degradation gradients in serpentine flow fields, whereas parallel channels exhibit preferential poisoning of initially strongest segments. Water vapor partially mitigates poisoning, improving spatial recovery to ∼0.27 A/segment. visokotemperaturna gorivna celica s protonsko izmenjevalno membrano obratovanje na reformnem plinu geometrija pretočih kanalov porazdelitev relaksacijskih časov segmentirana porazdelitev gostote toka high-temperature PEM fuel cell reformate operation flow-field geometry distribution of relaxation times DRT spatially resolved current density true false true Angleški jezik Slovenski jezik Članek v reviji 2026-04-21 11:19:33 2026-04-21 11:19:40 2026-04-22 04:28:34 0000-00-00 00:00:00 2026 0 0 19 str. art. 155095 Vol. 233 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.5 1879-3487 10.1016/j.ijhydene.2026.155095 275940355 RAZ_Todorovski_Emilija_2026.pdf RAZ_Todorovski_Emilija_2026.pdf 1 824F456F2F52A32289D9B0E6521CB410 c1644c8ab646347d2c7ce752230c05041b26cf8c4fe878975e79db6596e81055 85fd3f8c-3d64-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=232817 https://www.sciencedirect.com/science/article/pii/S0360319926017337?via%3Dihub 1 fcc6839e-3d62-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=232816 Fakulteta za strojništvo 0 0 0