Steam-Stable Zeolitic Imidazolate Framework ZIF-90 Membrane with Hydrogen Selectivity through Covalent Functionalization

A novel covalent functionalization strategy was developed to prepare reproducible ZIF-90 molecular sieve membranes by using 3-aminopropyltriethoxysilane as a covalent linker between the ZIF-90 layer and Al2O3 support via imines condensation. The ZIF-90 membranes show high thermal and hydrothermal stabilities, and they allow the separation of hydrogen from larger gases by molecular sieving.