FAU-type zeolite membranes synthesized by microwave assisted in situ crystallization

Abstract FAU-type zeolite membranes were prepared by an “in situ aging-microwave synthesis” (AM) method using a clear solution with the molar composition of 70Na2O: 1Al2O3: 20SiO2: 2000H2O. After two-stage AM synthesis, a defect-free FAU zeolite layer consisted of uniform zeolite crystals was formed on the support surface. The Si/Al ratio was ca. 1.5. The single-gas permeation and single-liquid vapor permeation properties of the as-synthesized zeolite membranes were investigated. The permselectivity of H2 and N2 was as high as 4.25 for FAU-type zeolite membranes. Pervaporation measurements were carried out for the dehydration of ethanol and isopropanol aqueous solutions. FAU-type zeolite membranes displayed relatively high permeation flux and water-selectivity.