A Cost-Effective and Highly Stable Symmetric Porous-Supported Mixed-Conductor Ceramic Membrane for Pure Oxygen Production.

The goal of carbon neutrality has strengthened the development of sustainable energy technologies, among which mixed ionic and electronic conducting oxygen transport membranes have gradually become research focuses because they have great potential in the production of high-purity oxygen, hydrogen purification, oxygen-containing catalytic reactions, and carbon dioxide capture. In this study, a graded porous-supported symmetric flat ceramic membrane was prepared by an aqueous tape-casting method using K2NiF4+δ-type oxide La2Ni0.95Mo0.05O4+δ as the membrane material. The membrane structure introduces graded porous support layers on both sides of the dense functional layer, ensuring efficient oxygen-ion transmission while maintaining excellent mechanical robustness. The results show that the oxygen flux of this material under the graded porous-supported symmetric structure is 3.18 mL min-1 cm-2 (i.e., 31.8 L min-1 m-2) when air is used as the feedstock gas, and it remains stable even under CO2 and coke oven gas. Compared with hollow-fiber membranes, this study not only has excellent air permeability, but also has significant advantages in simple production and high output. Due to its low cost, excellent CO2 tolerance, and long-term operational stability, it shows great potential in industrial applications.