Abstract
Zeolitic-imidazolate framework (ZIF-8) membranes have great potential to separate propylene/propane gas mixtures. Our recent work demonstrated that an excellent propylene/propane separation factor is obtained with a silicalite-seeded ZIF-8 membrane. However, the separation performance was limited due to non-selective defects in the ZIF-8 membranes that adversely affected the membrane separation performance. To further improve membrane performance, zinc oxide (ZnO) was atomically deposited on the synthesized ZIF-8 membrane surface using atomic layer deposition (ALD). ZnO ALD helped to minimize surface defects and inter-crystalline gaps of the membrane and improved the propylene/propane separation factor while maintaining the propylene permanence. After ZnO ALD treatment, ZIF-8 membranes showed significant improvement of the propylene/propane separation factor from 141 to 264, but at the expense of the propylene permeance with a ∼10% reduction. The improvement is likely due to defects healing on the ZIF-8 membrane surface via ZnO ALD. The resulting ZIF-8 membranes were characterized by XRD, XPS, BET, and SEM.
Original language | English |
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Article number | 112173 |
Journal | Microporous and Mesoporous Materials |
Volume | 343 |
DOIs | |
State | Published - Sep 2022 |
Externally published | Yes |
Funding
A.R. and S.D. contributed equally to this work. The authors acknowledge the funding provided by Oklahoma State University gratefully. The authors would like to thank Prof. Nicholas F. Materer from the Department of Chemistry at Oklahoma State University for helping with the BET analysis. Special thanks to Pamela Reynolds at Oklahoma State University for editing this manuscript.
Keywords
- Atomic layer deposition
- Propylene/propane gas separation
- Secondary growth
- ZIF-8 membrane