Résumé
Heavy-duty vehicle (HDV) proton exchange membrane fuel cells (PEMFCs) demand unprecedented oxygen reduction reaction (ORR) catalyst performance and durability, where conventional Pt-based systems fail to achieve this technical goal, due to severe potential cycling and dissolution. While Pt-based intermetallics offer promising activity, their long-term stability under dynamic load conditions remains unverified - especially the coupled effects of metal dissolution, support corrosion, and phase transitions at operating temperatures.To meet this stringent durability requirements of HDV PEMFCs, this study develops advanced Pt-intermetallic catalysts through controlled synthesis on novel carbon supports. Our approach integrates in-situ high-temperature X-ray diffraction (XRD) to monitor phase formation during the annealing process, online inductively coupled plasma mass spectrometry (ICP-MS) to track dissolution dynamics across both liquid half-cell techniques such as rotating disk electrode (RDE) and gas diffusion electrode (GDE), and membrane electrode assembly (MEA) configurations, and systematic accelerated stress tests simulating real-world degradation modes. By correlating atomic-scale structural evolution from in-situ characterization with electrochemical performance in cross-validated MEA testing, we establish fundamental design understanding for catalysts improvement towards better activity and durability.