Effect of hydrolysis rates on the morphology of sol-gel derived SrFeCo0.5Ox powder

Mixed-conducting (electronic and ionic) oxides with high oxygen ion conductivity have been investigated extensively for ion transport membranes used in the separation of oxygen from air and the conversion of natural gas to syngas. SrFeCo0.5Ox (SFC) is considered to be a technologically important material due to its high oxygen permeability as well as structural and chemical stability in reducing atmospheres. Conventionally, the SFC oxide is synthesized by the solid-state reaction of the constituent metal oxides, but this method often requires higher sintering temperature and longer heating schedule, and thus leads to poor chemical homogeneity and large particle size. Recent research has shown that the grain microstructure strongly influenced the oxygen permeation flux for mixed-conducting membranes and the oxygen flux increased considerably with decrease in grain size. The microstructure of a sintered material such as grain morphology (size and shape) depends mainly on the synthesis methods and conditions used.