A novel cobalt-free and CO2-stable LDC-LSCF membrane with high oxygen permeability

Abstract

Cobalt (Co)-free and carbon dioxide (CO2)-stable Ce0.8La0.2O2−δ –La0.1Sr0.9Cu x Fe1−x O3−δ (LDC-LSCF) dual-phase oxygen-permeable membranes have been successfully developed through the one-pot ethylenediaminetetraacetic acid–citric acid method. The appropriate amount of copper (Cu) doping can increase the content of oxygen (O) vacancies and improve the oxygen (O2) permeability of the materials. At 900°C, the oxygen permeation flux of 60 wt.% Ce0.8La0.2O2−δ –La0.1Sr0.9Cu0.2Fe0.8O3−δ (60LDC-LSCF-0.2) membrane reaches 0.58 (ml/min)/cm2 with pure helium (He) as the sweep gas, which is the highest oxygen permeation flux among dual-phase membranes with different copper-doping contents. The effects of different LDC contents on the static stability, conductivity and oxygen permeability of the dual-phase membranes are studied. The oxygen permeation flux of the 60LDC-LSCF-0.2 membrane remains 0.37 (ml/min)/cm2 with pure carbon dioxide as the sweep gas during the long-term oxygen permeation test. The present results indicate that LDC-LSCF oxygen-permeable membranes are promising membranes for oxygen production and carbon dioxide capture.