Preparation of lanthanum tungstate membranes by tape casting technique

Lanthanum tungstate materials have been reported to show exceptional mixed proton and electron conducting behaviour at elevated temperatures and making them attractive for dense hydrogen gas separation membranes. In this work preparation of planar asymmetric lanthanum tungstate membranes was addressed. For this purpose carbon black and rice starch pore formers were evaluated for optimum substrate gas permeability. It was found that carbon black pore former results in higher level of effective porosity. Stabilization of fine lanthanum tungstate powder in ethanol based solvent media was carried out to find out optimum surfactant quantity for tape casting slurry. By combining lanthanum tungstate tapes with and without pore former defect free asymmetric membranes were produced by conventional sintering.