Asymmetric mixed matrix membranes with zeolite imidazolate frameworks (ZIF‐8, ZIF‐67, bimetallic ZIF‐8/67) and polyethersulfone for high flux and high selective hydrogen separation

Abstract

Abstract For producing high‐purity hydrogen (H 2 ) from hydrocarbon reforming, membrane‐based separation can be used. In this study, mixed matrix polymer membranes using metal–organic framework (MOF) nanoparticles are explored to overcome the permeability‐selectivity trade‐off of traditional polymeric membranes. Highly permeable and highly H 2 selective MMM using ZIF‐8, ZIF‐67, and bimetallic ZIF‐8/67 MOFs were fabricated via a non‐solvent induced phase inversion method by incorporating an intermediate solvent evaporation step. MMMs with 5, 10, and 15 wt.% of nanofillers loadings were prepared and tested for single gas (H 2 , CO 2 , CH 4 , and N 2 ) permeability at 1–2 bar pressures. MMMs permeability and selectivities exceeded the Robeson upper bound (2008) for H 2 /CO 2 separation, demonstrating the potential for obtaining high‐purity hydrogen at low pressures. H 2 /N 2 selectivity of 43.4, H 2 /CO 2 selectivity of 27.86 for and H 2 /CH 4 selectivity of 31.36 were obtained. Analytical techniques such as XRD, FTIR, and DSC were used to explain the transport mechanism in the MMMs. The cross‐sectional structure and morphology of MMMs were analyzed with field‐emission scanning electron microscope (FESEM) to provide insights into the membrane's porous structure.