Metal–Organic Framework UiO-66 Layer: A Highly Oriented Membrane with Good Selectivity and Hydrogen Permeance

作者：Sebastian Friebe, Benjamin Geppert, Frank Steinbach, Jürgen Caro · 发表于：ACS Applied Materials & Interfaces · 年份：2017 · DOI：10.1021/acsami.7b02105 · 被引用次数：187 · 研究领域：Metal-Organic Frameworks: Synthesis and Applications、Membrane Separation and Gas Transport、Covalent Organic Framework Applications

The 3D metal–organic framework (MOF) structure UiO-66 [Zr 6 O 4 (OH) 4 (bdc) 6 ], featuring triangular pores of approximately 6 Å, has been successfully prepared as a thin supported membrane layer with high crystallographic orientation on ceramic α-Al 2 O 3 supports. The adhesion of the MOF layer to the ceramic support was investigated in different taxing conditions. Furthermore, by coating this UiO-66 membrane with a thin polyimide (Matrimid) top layer, we prepared a multilayer composite. Said membranes have been evaluated in the separation of hydrogen (H 2 ) from different binary mixtures at room temperature. H 2 as the smallest molecule (2.9 Å) should pass the UiO-66 membrane preferably since the kinetic diameters of all the other gases under study are larger. The gas mixture separation factors for the neat UiO-66 membrane were indeed found to be H 2 /CO 2 = 5.1, H 2 /N 2 = 4.7, H 2 /CH 4 = 12.9, H 2 /C 2 H 6 = 22.4, and H 2 /C 3 H 8 = 28.5. The coating with Matrimid led to a sharp cutoff for gases with kinetic diameters greater than 3.7 Å, resulting in increased separation performance.