Exploring the potential of decade-air exposed perovskite membranes through sustainable recycling approaches

The stability of perovskite-based oxygen permeable membranes under long-term storage conditions, especially in the presence of water and carbon dioxide, presents a significant challenge. In this study, we examined the impact of extended storage (more than 10 years) on Nb₂O₅-doped SrCo_0.8Fe_0.2O_3-δ (10Yr-SCFN) membranes. To unlock their industrial application potential, various approaches involving a combination of physical and chemical treatments to restore membrane properties in aged membranes are proposed and validated, while systematically investigating the evolution in chemical composition, microstructure, mechanical strength, and oxygen permeability. The 10Yr-SCFN membranes can be effectively restored through the secondary sintering method, wherein the membrane is first powdered and then calcinated in static air to maximize the removal of impurities. The mechanical strength and oxygen permeability reach levels of 30 MPa and 1.2 ml cm⁻² min⁻¹ (900 °C), respectively, comparable to the performance of freshly prepared membranes. These findings shed some light on the potentiality of sustainable recycling of perovskite membranes and provide theoretical and technical support for the practical application and industrialization of oxygen permeable membranes.