Formation mechanism of island CoO in La-Sr-Co-Fe oxygen transport membrane deposited by low pressure plasma spraying-thin film technology

Abstract

Dense oxygen transport membranes (OTMs) made from mixed oxygen ionic and electronic conductors (MIEC) have attracted intense research interest owing to their unmatched advantages on pure oxygen production, oxygen-fuel combustion and oxygen-related catalytic processes over traditional techniques. As one kind of the most-studied membranes, cobalt-containing membranes have unsatisfied thermal stability, though the oxygen permeability of these membranes is generally excellent due to the existence of cobalt. However, in situ forming CoO phase which were observed in the cobalt-containing membranes prepared by low pressure plasma spraying-thin film technology (LPPS-TF), were found to exhibit a remarkable stabilizing effect in the preliminary work. As one of the main premises to reveal the stabilization mechanism of these island CoO phase, their formation mechanism were studied in the first place in the paper.