Efficient preparation of large-area, high-selective SSZ-13 membrane

Abstract

Rub-coating and vacuum assisted dip-coating, are two conventional seeding methods in the preparation of zeolite membranes. Herein, we successfully synthesized SSZ-13 membrane with an effective area of 142.4 cm² and a length of 40 cm on α-alumina support by combining a vacuum-assisted dip-coating method and a rub-coating method. An investigation was conducted into the effects of five distinct seeding methods on the fabrication of SSZ-13 membranes. A thin, uniform and continuous seed layer was obtained through two distinct seeding methods: vacuum assisted dip-coating followed by rubbing the dried seeded support (referred to as VADC-rub1) and vacuum assisted dip-coating followed by rubbing the seeded support within the dipping solution (referred to as VADC-rub2), and the as-synthesized membranes were dense and uniform with thin membrane thickness (1.3–1.8 μm). Following the division of the 40 cm long SSZ-13 membrane into four 10 cm long SSZ-13 membranes, the characterizations of these membranes were conducted via XRD, SEM. In addition, single-gas permeation and CO₂-CH₄ mixture separation was performed. CO₂ and CH₄ had average permeances of (7.80 ± 2.23) × 10⁻⁷ mol m⁻² s⁻¹·Pa⁻¹, (1.36 ± 0.25) × 10⁻⁹ mol m⁻² s⁻¹·Pa⁻¹ in equimolar mixture, respectively and CO₂-CH₄ mixture selectivity was 561 ± 68, further confirming the membranes formed on four different positions of 40-cm-long were uniform, dense and of high-quality, showing their potential for gas separation applications.