Quest for Anionic MOF Membranes: Continuous sod-ZMOF Membrane with CO2 Adsorption-Driven Selectivity

We report the fabrication of the first continuous zeolite-like metalorganic framework (ZMOF) thin-film membrane. A pure phase sod-ZMOF, sodalite topology, membrane was grown and supported on a porous alumina substrate using a solvothermal crystallization method. The absence of pinhole defects in the film was confirmed and supported by the occurrence of quantifiable time-lags, for all studied gases, during constant volume/variable pressure permeation tests. For both pure and mixed gas feeds, the sod-ZMOF-1 membrane exhibits favorable permeation selectivity toward carbon dioxide over relevant industrial gases such as H-2, N-2, and CH4, and it is mainly governed by favorable CO2 adsorption.