Research Progress in Improvement of Oxygen Permeation Properties for Dual-phase Mixed Conducting Membranes

Dual-phase mixed conducting membrane can transport oxygen ions and electrons simultaneously at high temperature. Due to its high stability, low thermal expansion coefficient, high mechanical strength, and tunable component, it shows great potential in application of partial oxidation of methane to syngas (POM). However, how to improve its oxygen permeation flux is a key problem needing to be solved. In this review, the controlled step of the permeation process was analyzed based on the permeation mechanization. The improvements were presented, including utilized mixed conductor as electron conducting phase, reduced electronic threshold and decreased the grain size of the two phases. Meanwhile, fabricating asymmetric membrane, tube membrane and hollow fiber membrane were also efficient ways to reduce the thickness and to increase the surface area of the membrane, resulting in much increased permeation flux. Finally, some key problems to be solved in the future were also outlined.