Solid State Ionics, Vol.225, 690-694, 2012
Preparation and oxygen permeability of Ce0.8Sm0.2O2-delta-La0.7Ca0.3CrO3 (-) (delta) dual-phase composite hollow fiber membrane
Ce0.8Sm0.2O2 - delta (SDC)-La0.7Ca0.3CrO3 - delta (LCC) dual-phase composite hollow fibers were explored for oxygen separation membrane applications. Hollow fiber precursors were prepared by the phase-inversion/extrusion method using individual metal oxides and carbonates as starting materials, and were converted to gas-tight ceramic by sintering at 1560 degrees C in N-2 for 10 h. XRD analysis revealed that the sintered hollow fiber comprised of cubic SDC and perovskite LCC phase. SEM observation showed a homogeneous distribution of SDC and LCC grains in the fiber. An oxygen permeation of 2.3 x 10(-7) mol cm(-2).s(-1) was observed with a 26.7 mm-long hollow fiber by exposing its shell side to atmospheric air and feeding He at 30 ml/min into its lumen side at 950 degrees C. A much higher oxygen permeation flux of 3.9x10(-6)mol.cm(-2).s(-1) was observed when the sweep gas was changed from helium to 95%CO+5%CO2. The membrane remained intact after the oxygen permeation test at elevated temperatures under air/CO gradient. Since the hollow fiber membrane exhibited high oxygen permeation flux and satisfactory stability, it holds promise for membrane reactor applications. (C) 2012 Elsevier B.V. All rights reserved.
Keywords:Dual-phase composite;Ce0.8Sm0.2O2 (- delta);La0.7Ca0.3CrO3 (- delta);Hollow fiber;Oxygen permeation membrane