Synthesis of ZSM-5 zeolite membranes with large area on porous, tubular α-Al₂O₃ supports

Large-area ZSM-5 zeolite membranes were successfully prepared on porous α-Al₂O₃ supports with optimized synthesis solution composition and synthesis conditions. The membranes were achieved by repeated hydrothermal synthesis with cheap NBA (n-butylamine) as template and from clear synthesis solution. Not only the membranes were prepared on tubular supports, but also the membrane area is up to 260 cm². All the membranes were measured by X-ray diffraction (XRD), scanning electron microscopy (SEM) and single-gas permeation. As a result of these measures, the yield of high-quality membranes with a minimum permselectivity of H₂ to n -C₄H₁₀ of 27 (which is five times the Knudsen factor) as a quality criterion was increased to 50% of all preparations.