Dual-phase oxygen separation membrane composed of Y₂O₃-doped ZrO₂ and stainless steel

Abstract

A dual-phase membrane composed of an oxide ionic conducting ceramic phase [8 mol % yttria-stabilized zirconia (8YSZ)] and electronic conducting metal phase [316L stainless steel (SS)] was fabricated for an oxygen separation application. A sintering process called spark plasma sintering (SPS) or pulsed electric current sintering (PECS) was chosen as the means to densify the 8YSZ phase below the melting point of the SS phase. The SS content was varied from 15 vol % to 55 vol % to achieve a percolation structure for obtain the oxygen transport activity. Silver paste was applied to both sides of the membrane to act as a catalyst to improve the oxygen exchange rate. In this research study, a free-standing dense 8YSZ-SS dual-phase membrane with a thickness of 0.5 mm was fabricated by SPS at 1200 °C and the applied pressure of 80 MPa in 10 min. The 8YSZ-SS45 vol % dual-phase membrane achieved a good percolation structure of the 8YSZ and SS phases. By applying silver paste, 8YSZ-SS45 vol % dual-phase membrane exhibited the reasonably good oxygen permeation flux of 1.38 ml (STP)/min·cm² at 900 °C.