TY - JOUR

T1 - Tuning the Phase Composition of Metal-Organic Framework Membranes for Helium Separation through Incorporation of Fullerenes

AU - Han, Jiuli

AU - Wu, Haoyu

AU - Fan, Hongwei

AU - Ding, Li

AU - Hai, Guangtong

AU - Caro, Jürgen

AU - Wang, Haihui

N1 - Funding Information: We gratefully acknowledge the funding from the Natural Science Foundation of China (22141001 and 22138005), Project funded by China Postdoctoral Science Foundation (2022M721807), and Fundamental Research Funds for the Central Universities (buctrc202135).

PY - 2023/7/12

Y1 - 2023/7/12

N2 - Metal-organic framework (MOF) membranes have attracted significant research interest in gas separation, but efficient helium (He) separation remains a challenge due to the weak polarizability of He and the intrinsic pore size flexibility of MOFs. Herein, incorporated fullerenes (C60 and C70) were used to tune the crystallographic phase composition of ZIF-8 membranes, thus creating small and fixed apertures for selective He permeation. The fullerene-modified ZIF-8 (C60@ZIF-8 and C70@ZIF-8) membranes contain about 20% of the rigid-lattice ZIF-8_I-43m phase and have been prepared as 200-350 nm thick supported layers through electrochemical synthesis. They show a significantly enhanced molecular sieving for He/N2,CH4 together with a satisfactory He permeance of >200 GPU. Specifically, the He/N2 selectivity of the C70@ZIF-8 membrane is up to 30.4, which is much higher than that of the fullerene-free ZIF-8 membrane (5.1) and nearly an order of magnitude higher than those of other reported He-selective MOF membranes. A continuous long-term gas permeation test over 780 h under dry and humid conditions proved the excellent stability of the fullerene-modified ZIF-8 membranes. The general validity and versatility of the proposed strategy for MOF membrane preparation are also demonstrated by the enhancement of the separation performance of a fullerene-modified ZIF-76 membrane.

AB - Metal-organic framework (MOF) membranes have attracted significant research interest in gas separation, but efficient helium (He) separation remains a challenge due to the weak polarizability of He and the intrinsic pore size flexibility of MOFs. Herein, incorporated fullerenes (C60 and C70) were used to tune the crystallographic phase composition of ZIF-8 membranes, thus creating small and fixed apertures for selective He permeation. The fullerene-modified ZIF-8 (C60@ZIF-8 and C70@ZIF-8) membranes contain about 20% of the rigid-lattice ZIF-8_I-43m phase and have been prepared as 200-350 nm thick supported layers through electrochemical synthesis. They show a significantly enhanced molecular sieving for He/N2,CH4 together with a satisfactory He permeance of >200 GPU. Specifically, the He/N2 selectivity of the C70@ZIF-8 membrane is up to 30.4, which is much higher than that of the fullerene-free ZIF-8 membrane (5.1) and nearly an order of magnitude higher than those of other reported He-selective MOF membranes. A continuous long-term gas permeation test over 780 h under dry and humid conditions proved the excellent stability of the fullerene-modified ZIF-8 membranes. The general validity and versatility of the proposed strategy for MOF membrane preparation are also demonstrated by the enhancement of the separation performance of a fullerene-modified ZIF-76 membrane.

UR - http://www.scopus.com/inward/record.url?scp=85164296871&partnerID=8YFLogxK

U2 - 10.1021/jacs.3c03362

DO - 10.1021/jacs.3c03362

M3 - Article

C2 - 37351897

AN - SCOPUS:85164296871

VL - 145

SP - 14793

EP - 14801

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 27

ER -