Improvement of the Oxidative Stability of CeO2-Dispersed Hydrocarbon-Based Polyvinyl Alcohol Cross-Linked-Polybenzoxazine as a Proton-Exchange Membrane

This study introduces a simple technique for producing ceria nanoparticle-dispersed polyvinyl alcohol/sulfonated-polybenzoxazine (CeO2@PVA/poly S-BZ) composite membranes and examines their physicochemical, thermochemical, and electrochemical properties. Field emission scanning electron microscopy (FE-SEM) was utilized to analyze the surface and cross-sectional morphology of the produced polymer and polymer nanocomposite membranes. The objective is to create a membrane with improved oxidative stability, ionic conductivity, and mechanical durability for fuel cell applications. The composite membranes' production was validated via Fourier-transform infrared and thermogravimetric studies. The CeO2@PVA/poly S-BZ nanocomposite membrane demonstrated a proton conductivity of 1.72 x 10(-2 )S/cm at 80 degrees C, whereas the pristine PVA/poly S-BZ membrane showed a conductivity of 3.266 x 10(-2) S/cm at the same temperature. Analysis of temperature-dependent proton conductivity via an Arrhenius plot indicated that the membrane's proton-transport mechanism likely encompasses both Grotthuss and vehicular processes. The 1 wt% CeO2@PVA/poly S-BZ nanocomposite membranes exhibited remarkable oxidative stability, with merely 65.5% breakdown following 24 h of exposure to a Fenton reagent at 80 degrees C.