Co-doping of yttrium doped mixed barium cerate/zirconate perovskite (BCZY) with small amounts of Pr (BCZYP) substantially increases electrical conductivity while retaining structural and chemical stability. BCZYP is predominantly a proton conductor at temperatures up to 600-650 ̊C, whereas it is a mixed proton/oxide ion/electron conductor at higher temperatures. The co-doped BCZYP perovskite can...

Columnar thin films of undoped ceria were grown by metal-organic chemical vapor deposition. The films, deposited on Pt-coated MgO(100) substrates, display a columnar microstructure with nanometer scale grain size and ~30% overall porosity. Through-plane (thickness mode) electrical conductivity was measured by AC impedance spectroscopy. Proton conduction is observed below 350-400 °C, with a magn...

Proton exchange membranes (PEMs) play an important role in the fuel cell systems. A good PEM must meet a series of requirements such as high proton conductivity, excellent mechanical strength and stability, chemical and electrochemical stability, low fuel crossover, etc. Nafion is currently the most commercially utilized electrolyte membranes for polymer electrolyte fuel cells, with high chemic...

Proton exchange membranes were prepared by radiation-induced grafting of styrene onto commercial poly(tetrafluoroethylene-co-hexafluoropropylene) films using a simultaneous irradiation technique followed by a sulfonation reaction. The resulting membranes were characterized by measuring their physicochemical properties such as water uptake, ion exchange capacity, hydration number, and proton con...

Water sorption, volumetric expansion, and proton conductivity of 1100 EW Nafion and 555 EW sulfonated polyetheretherketone (SPEEK) were compared as functions of water activity at 60 and 80 C. Water sorption in Nafion occurs with a small positive volume of mixing, 0.005 cm/cm. In contrast, water sorption in SPEEK has a large negative volume of mixing 0.05 cm/cm. The percolation thresholds for pr...

An inorganic proton exchange membrane based on sintered mesoporous silica and phosphoric acid was developed with a high proton conductivity of 0.06 S cm(-1) at 200 °C, achieving an excellent power output of 689 mW cm(-2) in H2 at 190 °C and 200 mW cm(-2) in methanol at 200 °C with no external humidification.

Functionalized graphene oxide (FGO) reinforced quaternized poly(ether ether ketone) membranes were prepared for high temperature proton exchange membrane applications. The introduction of FGO significantly improved the mechanical strength and oxidative stability of these membranes at a high doping level. These reinforced membranes showed high tensile strength up to 40 MPa and high proton conduc...

Aromatic polymers containing perfluorosulfonic acid groups show well-developed and interconnected ionic clusters, and thus high proton conductivity at wide humidity range.

We report here a novel proton exchange membrane with remarkably high methanol-permeation resistivity and excellent proton conductivity enabled by carefully designed self-assembled ionic conductive channels. A direct methanol fuel cell utilizing the membrane performs well with a 20 M methanol solution, very close to the concentration of neat methanol.