Synthesis and Characterization of ZIF-7 Membranes by In Situ Method.

Zeolitic imidazolate frameworks (ZIFs) have been the focus of interest in adsorption, catalysis, and membrane applications due to their superior thermal and chemical stability, tunable microporous channels, and tailorable physical/chemical properties. In this study, ZIF-7 membranes were successfully prepared on macroporous a-alumina substrate by in situ solvothermal method, without the necessity of seeding or surface modification step. Addition of sodium formate during the reaction facilitates continuous well-intergrown crystalline ZIF-7 layer. As-synthesized ZIF-7 membrane was characterized by XRD, FE-SEM and gas permeation test. The H2 permeance through 5 µm ZIF-7 membrane was 1.9 x 10(-7) mol/m2 x s x Pa with ideal selectivity of H2/CO2 = 15.2.