Rong Huazhen, Zhang Jingjing, Guan Yixing, Gai Dongxu, Zou Xiaoqin
Faculty of Chemistry, Northeast Normal University, Changchun 130024, P. R. China.
ACS Appl Mater Interfaces. 2022 Jun 8;14(22):26171-26179. doi: 10.1021/acsami.2c03353. Epub 2022 May 23.
Zeolite membranes with reduced thickness and high continuity are of paramount importance for accelerating selective gas separation for resemblant molecules, and the synthesis of such membranes remains a grand challenge. Herein, we developed an interzeolite conversion synthesis approach to grow NaA zeolite membranes on NaX. The conversion of NaX into NaA proceeded via mild hydrothermal treatment of a dilute synthesis solution, preferentially forming a continuous polycrystalline NaA layer on the surface of NaX, which was precrystallized on a porous alumina support. The thickness of the NaA zeolite membrane was successfully controlled to the submicron scale (500 nm). The synthesized NaA membrane functioned as a selective separator for CH and CH gases. Taking the traditionally in situ grown membrane as a reference, the interzeolite-derived membrane exhibited a 3.5-fold separation factor and ∼4.0 times CH permeance. This approach provides an alternative synthesis option for zeolite membranes with advanced properties, and high efficiency in terms of superior gas selectivity and permeability is promising in precise gas separation.
厚度减小且具有高连续性的沸石膜对于加速相似分子的选择性气体分离至关重要，而此类膜的合成仍然是一个巨大的挑战。在此，我们开发了一种沸石间转化合成方法，以在NaX上生长NaA沸石膜。NaX向NaA的转化是通过对稀合成溶液进行温和水热处理实现的，优先在预先结晶在多孔氧化铝载体上的NaX表面形成连续的多晶NaA层。成功将NaA沸石膜的厚度控制在亚微米尺度（500nm）。合成的NaA膜用作CH和CH气体的选择性分离器。以传统的原位生长膜为参考，沸石间衍生的膜表现出3.5倍的分离因子和约4.0倍的CH渗透率。该方法为具有先进性能的沸石膜提供了一种替代合成选择，并且在精确气体分离方面，就卓越的气体选择性和渗透率而言具有高效性，前景广阔。
