Preparation of ZIF-62 polycrystalline and glass membranes for helium separation

作者：Zhi‐Jun Zhao, Li Ding, Alexander Mundstock, Oliver Stölting, Sebastian Polarz, Haihui Wang, Armin Feldhoff · 发表于：Journal of Membrane Science · 年份：2024 · DOI：10.1016/j.memsci.2024.122677 · 被引用次数：31 · 研究领域：MXene and MAX Phase Materials、Membrane Separation and Gas Transport、Membrane Separation Technologies

Defects among the grains of MOF polycrystalline membranes lead to non-selective gas transport, thereby reducing their selectivity in gas separation. In this work, ZIF-62 polycrystalline membranes with a well-intergrown structure were prepared on MXene modified supports. Subsequent thermal treatment transformed the membranes into glass membranes, effectively eliminating non-selective defects at grain boundaries. Due to the incorporation of the MXene film and the vertical positioning of the support during the solvothermal process, only a minimal portion of the glass melt infiltrated into the porous support. Across the temperature range of 303 K–423 K and pressure range of 1 bar–3 bar, the ZIF-62 glass membranes showcased superior helium separation property and long-term chemical stability (resistant to CO2 and H2O). The helium permeance reached approximately 51 GPU, with selectivities against N2 and CH4 being 17.4 and 13.9, respectively, outperforming current MOF membranes.