%0 Journal Article
%A Garcia-Fayos, Julio
%A Balaguer, María
%A Baumann, Stefan
%A Serra, José M.
%T Dual-phase membrane based on LaCo $_{0.2}$ Ni $_{0.4}$ Fe $_{0.4}$ O $_{3−x}$ -Ce $-{0.8}$ Gd $_{0.2}$ O $_{2−x}$ composition for oxygen permeation under CO $_{2}$ /SO $_{2}$ -rich gas environments
%J Journal of membrane science
%V 548
%@ 0376-7388
%C New York, NY [u.a.]
%I Elsevier
%M FZJ-2017-08377
%P 117 - 124
%D 2018
%X A dual-phase material with high ambipolar conductivity composed by the perovskite LaCo0.2Ni0.4Fe0.4O3-δ (LCNF) as the electronic phase and the fluorite Ce0.8Gd0.2O2-δ (CGO20) as oxide-ion conductor is proposed for use as oxygen transport membrane. The chemical compatibility between both materials depends on the synthesis method, i.e. one-pot sol-gel synthesis leads to the formation of the fluorite and the perovskite phases, as well as a third NiO-based phase. The formation of this last phase can be avoided by previously stabilizing the phases separately. The composite material shows high electrical conductivity, i.e., 7.25 S cm−1 at 800 °C for LCNF-CGO20 with NiO impurity, and 2.6 S cm−1 at 800 °C for LCNF-CGO20. A maximum oxygen flux, J(O2), of 0.74 ml min−1 cm−2 is obtained at 1000 °C for a surface-activated membrane in Air/Ar gradient at ambient pressure. The membranes were tested under i) 30% CO2 in Ar, and ii) 250 ppm of SO2 in 30% CO2 in Ar, reproducing oxyfuel-like conditions. Oxygen flux decreases in these atmospheres, especially at temperatures below 900 °C, due to competitive adsorption of these gases with the O2. After CO2 and SO2 exposure, initial oxygen fluxes are recovered when switching back to Ar sweeping at temperatures above 900 °C. Nevertheless, at temperatures < 900 °C the original J(O2) before SO2 exposure is not fully recovered and postmortem FESEM images reveal the membrane surface degradation in SO2.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000419646500014
%R 10.1016/j.memsci.2017.11.006
%U https://juser.fz-juelich.de/record/841285