Sulfated Titania-Silica Reinforced Nafion Nanocomposite Membranes for Proton Exchange Membrane Fuel Cells

摘要

Sulfated titania silica (SO42-/TiO2-SiO2) composites were prepared by a sol gel method with sulfate reaction and characterized by X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). The nanonnetric diameter and geometry of the sulfated titania silica (STS) was investigated by transmission electron microscopy (TEM). A small amount of the STS composite in the range of 0.5-3 wt% was then added as reinforcing into the Nafion (R) membrane by water-assisted solution casting method to prepare STS reinforced Nafion (R) nanocomposite membranes (STS-Nafion (R) nanocomposite membranes). The additional functional groups, sulfate groups, of the nanocomposite membrane having more surface oxygenated groups enhanced the fuel cell membrane properties. The STS-Nafion (R) nanocomposite membranes exhibited improved water uptake compared to that of neat Nafion (R) membranes, whereas methanol uptake values were decreased dramatically improved thermal property of the prepared nanocomposite membranes were measured by thermogravimetric analysis (TGA). Furthermore, increased ion exchange capacity values were obtained by thernnoacidic pretreatment of the nanocomposite membranes.