Oxygen transport and stability of asymmetric SrFe(Al)O3-delta-SrAl2O4 composite membranes
authors Kovalevsky, A; Kharton, VV; Snijkers, FMM; Cooymans, JFC; Luyten, JJ; Marques, FMB
nationality International
journal JOURNAL OF MEMBRANE SCIENCE
author keywords oxygen permeability; mixed ionic-electronic conductor; asymmetric ceramic membrane; ferrite-based composite; microstructural stability
keywords CERAMIC MEMBRANES; THERMOMECHANICAL PROPERTIES; PERMEABILITY; SUPPORT; PEROVSKITES; METHANE; LAYERS
abstract In order to appraise a two-stage compaction procedure using pore-forming additives for the fabrication of asymmetric mixed-conducting membranes where the porous and dense layers are made of the same composition, the oxygen permeability of a series of (SrFeO3-delta)(0.7)(SrAl2O4)(0.3) composite samples with varying architecture was studied at 1073-1223 K. The preparation route for the crack-free supported membranes included pressing of the starch-containing and pure dual-phase composite powders, sintering at 1623 K, and subsequent surface modification of the dense layers having the thickness of 0.12-0.15 mm. Analysis of the oxygen permeation fluxes show a significant limiting effect of oxygen diffusion through the support, where the porosity and average pore size are 20% and 2-4 mu m, respectively. The overall level of oxygen transport, higher than that in the symmetric surface-activated membranes, was only achieved at 1173-1223 K for the porous layer thickness of 0.4 mm. Slow microstructural degradation due to the support sintering, evidenced by dilatometry, leads to a moderate decrease in the oxygen fluxes with time. At 1973 K, the corresponding changes were approximately 16% during 220 It. The results suggest that increased total porosity, preferential pore orientation perpendicular to the dense layer and incorporation of nano-sized catalyst particles into the pores are needed to increase the performance of asymmetric ferrite-based membranes. (c) 2007 Elsevier B.V. All rights reserved.
publisher ELSEVIER SCIENCE BV
issn 0376-7388
year published 2007
volume 301
issue 1-2
beginning page 238
ending page 244
digital object identifier (doi) 10.1016/j.memsci.2007.06.028
web of science category Engineering, Chemical; Polymer Science
subject category Engineering; Polymer Science
unique article identifier WOS:000249290600026
  ciceco authors
  impact metrics
journal analysis (jcr 2017):
journal impact factor 6.578
5 year journal impact factor 6.656
category normalized journal impact factor percentile 95.461
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg