Boosting the Performance of High-Temperature Proton Exchange Membrane Fuel Cell via Catalyst Layer Modification with Zeolite

This study systematically investigated the impact of introducing NaY zeolite into the cathode catalyst layer (CL) on the activity and durability of high-temperature proton exchange membrane fuel cells (HT-PEMFCs). According to Brunauer–Emmett–Teller (BET), the CL exhibited a marked increase in both specific surface area and pore volume when the zeolite loading was optimized. Characterization results confirmed that zeolite underwent protonation in a phosphoric acid (PA) environment, introducing additional Brønsted acid sites, and that both the zeolite and catalyst were uniformly distributed within the CL. Performance tests under H2/air conditions demonstrated that the MEA-2 sample (15 wt % zeolite) outperformed the zeolite-free MEA-0, achieving a peak power density of 0.455 W cm–2 compared to 0.395 W cm–2. Furthermore, the MEA-2 sample exhibited excellent durability, with almost no performance degradation during 500 h of steady-state and start–stop durability tests at 0.2 A cm–2 in reformate/air conditions. Electrochemical analysis revealed that the performance improvement of MEA-2 was attributed to the optimization of both the reaction kinetics and mass transport regions. Theoretical calculations further revealed that the unique microstructure of zeolite and its high PA adsorption capability enable competitive adsorption with the platinum–cobalt (PtCo) catalyst, effectively alleviating the PA poisoning effect on PtCo and promoting the uniform distribution of PA, thus ensuring an efficient proton conduction path. This study provides a novel and effective strategy for optimizing the catalyst–PA interface in HT-PEMFCs.