Metal-Organic Framework UiO-66 Layer: A Highly Oriented Membrane with Good Selectivity and Hydrogen Permeance.
The 3D metal-organic framework (MOF) structure UiO-66 [Zr6O4(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-Al2O3supports. 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 (H2) from different binary mixtures at room temperature. H2as 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 H2/CO2= 5.1, H2/N2= 4.7, H2/CH4= 12.9, H2/C2H6= 22.4, and H2/C3H8= 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.
Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover , Callinstraße 3A, D-30167 Hannover, Germany.
Sebastian
S
Friebe
Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover , Callinstraße 3A, D-30167 Hannover, Germany.
Benjamin
B
Geppert
Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover , Callinstraße 3A, D-30167 Hannover, Germany.
Frank
F
Steinbach
Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover , Callinstraße 3A, D-30167 Hannover, Germany.
Jürgen
J
Caro
MOF membrane; UiO-66; crystallographic orientation; hydrogen separation; polymer coating; stability