Publication
Title
Oxygen exchange-limited transport and surface activation of $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-\delta}$ capillary membranes
Author
Abstract
 Analysis of oxygen permeation fluxes through Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) capillary membranes, fabricated via a phase-inversion spinning technique using polysulfone as binder, showed a significant limiting role of the surface-oxygen exchange kinetics. Within the studied temperature and oxygen partial pressure ranges, the activation of core and shell sides of the BSCF capillary with praseodymium oxide (PrOx) resulted in an increase in permeation rate of about 300%. At 11231223 K the activated BSCF membranes demonstrate almost 3-times lower activation energies for the overall oxygen transport (not, vert, similar35 kJ/mol) than the non-activated capillaries, indicating that the mechanism of oxygen transport through the activated capillaries becomes significantly controlled by bulk diffusion limitations, allowing further improvement of the overall performance by decreasing the wall thickness. XRD, EDS and EPMA studies revealed the formation of (Pr,Ba,Sr)(Co,Fe)O3−δ perovskite-type oxides on the surface of the PrOx-modified membranes, which may be responsible for the drastic increase in oxygen exchange rate. At T > 1123 K both non-activated and activated Ba0.5Sr0.5Co0.8Fe0.2O3−δ membranes demonstrate stable performance with time, while at 1073 K only a small initial decrease in permeation was observed.
Language
English
Source (journal)
Journal of membrane science. - Amsterdam
Publication
Amsterdam : 2011
ISSN
0376-7388
Volume/pages
368:1/2(2011), p. 223-232
ISI
000286701800027
Full text (Publisher's DOI)
UAntwerpen
 Faculty/Department Research group Publication type Subject Affiliation Publications with a UAntwerp address