Mixed conductive perovskite materials, e.g., La1−xSrxO3−δ (LSCO), were widely investigated to understand the effects of doping and composition upon the O permeability. A new approach was developed here that permitted the formation of a complete gas-tight O-permeable thin membrane on the outer surface of a porous CeO2 tube by the means of slurry coating. The O-permeable membrane was a dual-phase composite containing equal volume fractions of CeO2 and LSCO-80 (x = 0.8). In the membrane, CeO2 particles were uniformly embedded in the continuous LSCO phase, and the highly dispersed semi-continuous structure could buffer the mechanical stress generated in the LSCO phase due to the mismatch of the coefficients of thermal expansion between the membrane and the support. The O permeation flux tests revealed a low activation energy barrier (about 30kJ/mol) of the whole electrochemical reaction at 400 to 900C. The surface desorption (or the anodic) process of O was simulated by using

the extended Hückel theory. The activation energy obtained from the extended Hückel theory simulation was found to be very close to experimental data. According to computer simulations, the surface O desorption activation energy relied upon the surface O vacancy density and thus the O partial pressure.

Oxygen Permeation through the LSCO-80/CeO2 Asymmetric Tubular Membrane Reactor. X.Yin, L.Hong, Z.L.Liu: Journal of Membrane Science, 2006, 268[1], 2-12