Simultaneously enhancing the oxygen flux and operational stability of Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3–δ membrane via an Ag doping method

Recent extreme weather events emphasize the urgent need for climate action, necessitating a shift from fossil fuels to cleaner energy sources. Carbon capture and storage (CCS) projects offer a viable solution, particularly those employing Oxyfuel combustion. Oxygen transport membranes via mixed ionic and electronic conducting (MIEC) principles are envisaged to improve the viability of Oxyfuel combustion projects by providing a cost-effective method for oxygen separation. This paper explores the performance enhancement of Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3–δ (BSCF) perovskite membranes, typically known for high oxygen flux but suffering from low stability. A universal strategy employing a facile Ag doping method is investigated. The Ag-doped BSCF (BSCF–2%Ag) membranes exhibit improved stability and oxygen permeation behavior compared to their undoped counterparts. The structural and compositional analyses confirm the successful incorporation of Ag into the BSCF lattice, not only playing the role as the sintering aid but also inhibiting Sr segregation and enhancing operational stability. Long-term permeation tests demonstrate the sustained performance of BSCF-2%Ag membrane, showcasing a 31.2% improvement in oxygen flux at 800 °C. The proposed Ag doping strategy offers a promising pathway for simultaneously enhancing the stability and flux of Co-perovskite membranes, which is crucial for advancing CCS technologies.