(520e) Fabrication of HKUST-1 Membranes Using a Secondary Growth Method

Metal-organic frameworks (MOFs) represent a new class of crystalline porous inorganic-organic hybrid compounds that have attracted increasing academic and industrial interest in the last few years due to extraordinarily low densities and high surface areas, leading to interest in using these materials for gas storage, separation and catalysis applications.1

However, little progress has been made to construct MOF-based films and membranes that are useful for applications in separation or sensing.2 One of the major challenges to the preparation of MOF thin films and membranes is that often times there are no proper functional groups in MOFs that can interact with support surfaces. HKUST-1 (Cu3(BTC)2, BTC=1,3,5-benzenetricarboxylate),3 is one of the most widely studied MOFs. Molecular simulation of permeance with gas mixtures (H2/N2, H2/CH4 and H2/CO2) shows that HKUST-1 has a good selectivity for H2/CO2 mixtures.4 However, there is only one experimental report of a HKUST-1 membrane using a copper net as a support and a source for copper via in-situ hydrothermal synthesis, showing very promising separation capability.5

In this talk, we will present a novel method based on the secondary growth to fabricate HKUST-1 membranes on porous α-alumina supports. The key feature of our method is to make a strong bonding between HKUST-1 seeds and porous support via dropping mother solution including HKUST-1 crystals at high temperature(e.g., 200 oC) on the surface of porous support. We will discuss how this method can induce strong bonding between the porous support and the seed crystals via condensation. Subsequent secondary growth of the HKUST-1 seed crystals in a diluted growth solution has led to the formation of continuous HKUST-1 membranes. Finally we will discuss the performance of HKUST-1 membranes based on binary component permeation measurement.

1. Long, J. R.; Yaghi, O. M., Chem. Soc. Rev. 2009, 38, 1213-1214.

2. Zacher, D.; Shekhah, O.; Wöll, C.; Fischer, R. A., Chem. Soc. Rev. 2009, 38, 1418-1429.

3. Chui, S. S. Y.; Lo, S. M. F.; Charmant, J. P. H.; Orpen, A. G.; Williams, I. D., A. Science 1999, 283, (5405), 1148-1150

4 Keskin, S.; Liu, J. C.; Johnson, J. K.; Sholl, D. S., Langmuir 2008, 24, (15), 8254-8261

5 Guo, H. L.; Zhu, G. S.; Hewitt, I. J.; Qiu, S. L., Journal of the American Chemical Society 2009, 131, (5), 1646.