Ultra-High Durability and Performance of a Proton Composite Membrane containing long-Chain Amino Sulfonated Poly(arylene ether) and Cerium Oxide-Titanium Carbide over 1000 Hours for Hydrogen Fuel Cells

As a key component of proton exchange membrane fuel cells (PEMFCs), the durability of the proton exchange membranes (PEMs) directly determines the service life of the PEMFCs. In this study, poly(arylene ether) containing amino and trifluoromethyl units (AFPAE) was synthesized by nucleophilic aromatic polycondensation followed by nucleophilic substitution to obtain butyl sulfonated poly (arylene)(SAFPAE). CeO₂-TiC prepared by the hydrothermal process were incorporated into the SAFPAE matrix and the content of the CeO₂-TiC was optimized. The morphological, physicochemical, and electrochemical investigation of the prepared membranes demonstrated that the random dispersion of the CeO₂-TiC in the SAFPAE matrix improves the thermal and mechanical stability as well as water adsorption, ion exchange capacity and proton conductivity. Particularly, the optimized SAFPAE/CeO₂-TiC exhibited high current output and power output at 20% relative humidity and 60 °C outperforming commercial membranes. Most importantly, the SAFPAE/CeO₂-TiC composite membrane demonstrated MEA durability over 1100 h under low humidity 20% RH operating conditions and was about 4.4 times more stable than pristine SAFPAE. SAFPAE with a special structure of hydrophilic backbone containing trifluoromethyl group and long aliphatic sulfonic acid group to create nano-sized proton conduction channels whereas, TiC provides mechanical support and CeO₂ improves the durability of PEM by scavenging free radicals. Therefore, the SAFPAE/CeO₂-TiC composite membrane reported in this study is a potential candidate for high-performance and durable PEMFC, suggesting its applicability in future large-scale PEMFC.