Preparation And Properties Of Hydrogen Separation Membranes

Proton conductors La2Ce2O7in different sintering temperatures, proton conductors La2Ce2O7doped with different concentrations ZnO(0~5wt.%) sintering aids in different sintering temperatures,porton conductors BaCe0.89Gd0.1Cu0.01(OX)3-δ(X=F, Cl, Br) doped with different elements and protonconductors (La1-xNdx)5.5WO12-δ(x=1/3,1/2) doped with different concentrations were successfullysynthesized by the solid state reaction method. Through using the technology of XRD, SEM and EIS,phase structure, micro-morphology and electrical conductivity of the materials were studiedrespectively. Chemical stability against CO2and H2O was tested. In addition, the hydrogenpermeation fluxes of the samples were measured in different hydrogen concentrations and differenttemperatures by gas chromatographic method. The results indicate that:The La2Ce2O7sintered at1500℃,1550℃and1600℃show cubic fluorite structure and havegood chemical compatibility against CO2and H2O, whose density and conductivity are improved withthe increase of sintering temperature. The hydrogen flux for La2Ce2O7sintered at1600℃withthickness of1.47mm improves with the test temperatures and hydrogen concentrations raised. Using50%H2/N2as feed gas, the hydrogen flux is0.056mL·min-1·cm-2at825℃. The La2Ce2O7doped withZnO(0~5wt.%) sintering aids sintered at1300℃and1350℃show cubic fluorite structure, whosedensity and conductivity are improved with the increase of sintering temperature and the amount ofZnO. The hydrogen flux for La2Ce2O7doped with5wt.%ZnO sintered at1350℃with thickness of1.52mm improves with the test temperatures and hydrogen concentrations raised. Using50%H2/N2asfeed gas, the hydrogen flux is0.066mL·min-1·cm-2at825℃. BaCe0.89Gd0.1Cu0.01(OX)3-δ(X=F, Cl, Br)sintered at1450℃show orthorhombic perovskite-type structure and have good chemicalcompatibility against H2O. TGA experiments in pure CO2show that compatibility against CO2ofBaCe0.89Gd0.1Cu0.01O3-δdoping F, Cl and Br increases and doping Br has the best chemicalcompatibility against CO2. Compared with the conductivity of BaCe0.89Gd0.1Cu0.01O3-δ, doping F, Cland Br decrease very small.(La1-xNdx)5.5WO12-δ(x=1/3,1/2) sintered at1450℃show cubic fluoritestructure and have good chemical compatibility against CO2and H2O. The density and conductivityincrease with increasing of the amount of Nd. The hydrogen flux for (La1/2Nd1/2)5.5WO12-δwiththickness of1.56mm improves with the test temperatures and hydrogen concentrations raised. Using50%H2/N2as feed gas, the hydrogen flux is0.079mL·min-1·cm-2at900℃.Figure38; Table15; Reference73...