Synthesis and oxygen permeation properties of Ce0.8Sm0.2O2-d - Sm1-xSrxCu0.2Fe0.8O3-d dual-phase ceramic membranes: effect of Strontium contents and Pd coating layer

Abstract

In this study, the effects of the strontium (x = 0.2-0.7) contents on oxygen permeation properties of 60 wt% Ce0.8Sm0.2O2-d - 40 wt% Sm0.8Sr0.2Cu0.2Fe0.8O3-d (SDC-8228) and 60 wt% Ce0.8Sm0.2O2-d - 40 wt% Sm0.3Sr0.7Cu0.2Fe0.8O3-d (SDC-3728) dual-phase (DP) ceramic membranes obtained by one-pot synthesis of a pure Ionic Conducting (IC) phase with a Mixed Ionic-Electronic Conducting (MIEC) phase were investigated under different conditions of temperature (800-1000 degrees C) and CO2 atmosphere (0-100%). As a result, it was confirmed that the oxygen permeation properties of selected IC/MIEC DP membranes had increased when the Strontium content (Sr-x) of the MIEC phase increased from Sr-x (=) (0.2) to Sr-x (=) (0.7). The results showed that the SDC-3728 DP membrane exhibits higher oxygen flux than the SDC-8228 DP membrane. In detail, the oxygen permeation flux reached similar to 0.5 mL min(-1) cm(-2) at 1000 degrees C, which was about was one and a half times higher than the SDC-8228 DP membrane. An additional performance improvement was achieved by coating the SDC-3728 DP membrane with a pure Electron Conductor (EC) like Palladium (Pd) by the electroless deposition technique. The oxygen permeation flux of the Pd surface-modified SDC-3728 DP membrane was similar to 2.0 mL min(-1) cm(-2) in 100% CO2 at 1000 degrees C, which was about three times higher than the SDC-8228 DP membrane.