膜科学与技术

碱修饰-原位老化微波法合成FAU沸石膜及合成机理研究

作者：刘韬弘，易杰，施可彬，张波，张立峰，曹毅，李砚硕

单位：宁波大学材料科学与化学工程学院，宁波 315211 [ ]；杭州三隆新材料有限公司，杭州 310020 2；浙江汇甬新材料有限公司，宁波 315034 3

关键词： FAU膜；原位生长；渗透汽化；生长机理

出版年,卷(期):页码： 2024,44(3):73-82

摘要：

提出一种新型碱修饰-原位老化微波法合成致密纯相FAU沸石膜的方法。通过XRD、SEM、ATR-FTIR和渗透汽化测试研究了氢氧化钠在载体修饰方面的作用及FAU沸石膜生长机理。通过对比未修饰载体，发现氢氧化钠修饰能明显促进FAU晶体在载体表面的成核和生长。本研究通过对FAU沸石膜生长过程表征，发现在老化过程中体相溶胶首先在载体表面碱促进下形成FAU次级结构单元，接着形成片状FAU晶体，随着老化时间的延长逐渐变成块状晶体并交联生长，最后在微波的作用下消除细微缺陷得到致密的纯相FAU膜。同时本论文考察碱浓度对载体的修饰作用，通过优化发现使用质量分数为2.95%Na2O溶液修饰后的载体，可以得到具有最佳的渗透汽化性能的FAU膜：在60 °C下对乙醇/水（质量比90/10）混合溶液进行测试，FAU膜的平均渗透通量为2.19 kg/m2·h，渗透侧水含量100%，说明其具有高通量和高选择性，展现出良好的工业化应用前景。

This study proposed a novel method for synthesizing dense and pure phase FAU zeolite membranes using in situ aging microwave method by alkali modification. The role of sodium hydroxide on carrier and the growth mechanism of FAU zeolite membranes were investigated through XRD, SEM, ATR-FTIR, and pervaporation testing. By comparing the unmodified carriers, it was found that with the modification of sodium hydroxide, the nucleation and growth of FAU crystals were significantly promoted on the carrier surface. The growth process of FAU zeolite membrane was characterized, it was found that during the aging process, the bulk gel first formed FAU secondary structural units under the promotion of alkali on the carrier surface, followed by the formation of flaky FAU crystals. With the prolongation of aging time, it gradually became block like crystals and crosslinked. Finally, under the action of microwave, fine defects were eliminated to obtain a dense pure phase FAU membrane. At the same time, the effect of alkali concentration on the carrier was investigated. Through optimization, it was found that the carrier modified in a Na2O concentration of 2.95 wt% solution can obtain the FAU membrane with the best pervaporation performance. In a mixed ethanol/water (90/10) solution at 60 °C, the average permeation flux of the FAU membrane is 2.19 kg/m2h, and the water content on the permeation side is 100%. This indicates that it has high flux and selectivity, demonstrating good industrial application prospects.

刘韬弘（1996-11），男，广东揭阳人，研发工程师，硕士研究生，，从事用于气体分离的分子筛膜的研究

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