Ultrathin metal–organic framework membrane production by gel–vapour deposition

• Published in: Nature communications Vol. 8; no. 1; pp. 406 - 8
• Main Authors: Li, Wanbin, Su, Pengcheng, Li, Zhanjun, Xu, Zehai, Wang, Fei, Ou, Huase, Zhang, Jiaheng, Zhang, Guoliang, Zeng, Eddy
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.09.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 639/166/898; 639/301/357/551; 639/638/298/921; Carbon dioxide; Fluxes; Humanities and Social Sciences; Membranes; multidisciplinary; Science; Science (multidisciplinary); Vapor deposition
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-017-00544-1

Ultrathin, molecular sieving membranes composed of microporous materials offer great potential to realize high permeances and selectivities in separation applications, but strategies for their production have remained a challenge. Here we show a route for the scalable production of nanometre-thick metal–organic framework (MOF) molecular sieving membranes, specifically via gel–vapour deposition, which combines sol–gel coating with vapour deposition for solvent-/modification-free and precursor-/time-saving synthesis. The uniform MOF membranes thus prepared have controllable thicknesses, down to ~17 nm, and show one to three orders of magnitude higher gas permeances than those of conventional membranes, up to 215.4 × 10 −7  mol m −2  s −1  Pa −1 for H 2 , and H 2 /C 3 H 8 , CO 2 /C 3 H 8 and C 3 H 6 /C 3 H 8 selectivities of as high as 3,400, 1,030 and 70, respectively. We further demonstrate the in situ scale-up processing of a MOF membrane module (30 polymeric hollow fibres with membrane area of 340 cm 2 ) without deterioration in selectivity. MOF-based membranes have shown great promise in separation applications, but producing thin membranes that allow for high fluxes remains challenging. Here, the authors use a gel–vapour deposition strategy to fabricate composite membranes with less than 20 nm thicknesses and high gas permeances and selectivities.