Synthesis and characterization of Nafion/SiO₂ – MO_x (M= Ti, Zr, W) nanocomposite membranes by sol-gel reaction for fuel cells

Development of efficient and durable cation exchange membranes for fuel cells is important particularly a method for inhibiting the volatility of water at higher temperature is a crucial issue. Nafion composite membranes were prepared by impregnation with SiO₂, SiO₂ -TiO₂, SiO₂ – WO₃, and SiO₂ – ZrO₂ by immersing these in-situ sol-gel solution and stirring. The sol-gel solution mixture served to swell the pores of the membrane to maximize the adsorption of the precursor solution. The composite membranes have been characterized by X-ray diffraction, scanning electron microscopy, water uptake, ion exchange capacity and conductivity. XRD studies showed the crystallinity and particle sizes of oxides. FTIR showed the bond formation in oxide mixtures. SEM provides information about the morphology of the particles. Water uptake increased gradually from pure membrane to SiO₂, SiO₂ – TiO₂, SiO₂ -WO₃, and SiO₂ – ZrO₂ particles added membranes and was maximum for SiO₂ – ZrO₂ added membrane. Composite membranes exhibited higher water uptake, ion exchange capacity, conductivity and can improve the efficiency and durability of PEM fuel cells considerably