Wang Qing, Chen Huiyuan, He Feiyang, Liu Qiao, Xu Nong, Fan Long, Wang Chuyan, Zhang Lingyun, Zhou Rongfei
School of Energy, Materials and Chemical Engineering, Hefei University, Hefei 230601, China.
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 210009, China.
Membranes (Basel). 2023 Oct 26;13(11):858. doi: 10.3390/membranes13110858.
In this study, high-performance FAU (NaY type) zeolite membranes were successfully synthesized using small-sized seeds of 50 nm, and their gas separation performance was systematically evaluated. Employing nano-sized NaY seeds and an ultra-dilute reaction solution with a molar composition of 80 NaO: 1AlO: 19 SiO: 5000HO, the effects of synthesis temperature, crystallization time, and porous support (α-AlO or mullite) on the formation of FAU membranes were investigated. The results illustrated that further extending the crystallization time or increasing the synthesis temperature led to the formation of a NaP impurity phase on the FAU membrane layer. The most promising FAU membrane with a thickness of 2.7 µm was synthesized on an α-AlO support at 368 K for 8 h and had good reproducibility. The H permeance of the membrane was as high as 5.34 × 10 mol/(m s Pa), and the H/CH and H/-CH selectivities were 183 and 315, respectively. The CH/CH selectivity of the membrane was as high as 46, with a remarkably high CH permeance of 1.35 × 10 mol/(m s Pa). The excellent separation performance of the membrane is mainly attributed to the thin, defect-free membrane layer and the relatively wide pore size (0.74 nm).
在本研究中，使用50 nm的小尺寸晶种成功合成了高性能的FAU（NaY型）沸石膜，并对其气体分离性能进行了系统评估。采用纳米尺寸的NaY晶种和摩尔组成为80NaO:1AlO:19SiO:5000HO的超稀反应溶液，研究了合成温度、结晶时间和多孔载体（α-AlO或莫来石）对FAU膜形成的影响。结果表明，进一步延长结晶时间或提高合成温度会导致FAU膜层上形成NaP杂质相。在α-AlO载体上于368 K下结晶8 h合成了最有前景的厚度为2.7 µm的FAU膜，且具有良好的重现性。该膜的H渗透率高达5.34×10 mol/(m² s Pa)，H/CH和H/C₂H₄选择性分别为183和315。该膜的CH₄/C₂H₄选择性高达46，CH₄渗透率高达1.35×10 mol/(m² s Pa)。该膜优异的分离性能主要归因于其薄且无缺陷的膜层以及相对较宽的孔径（0.74 nm）。
