Synthesis of MIL-88B(Fe)/Matrimid mixed-matrix membranes with high hydrogen permselectivity

A cheap and biocompatible metal–organic framework MIL-88B(Fe) (MIL = Material Institut Lavoisier) was synthesized and incorporated into Matrimid® 5218 to fabricate mixed-matrix membranes (MMMs) for gas separation. Separation performances of the MIL-88B(Fe)/Matrimid MMMs were tested for the single gas permeation of H2 and CH4 as well as the mixture gas separation of an equimolar binary H2–CH4 mixture. Due to the molecular sieving effect, the incorporation of MIL-88B(Fe) can enhance H2 permeability but hinder the transport of CH4 in MIL-88B(Fe)/Matrimid MMMs, thus resulting in enhanced separation selectivity of H2–CH4. At 298 K and ΔP = 3.0 bar, compared with those of a pure polymeric membrane, the H2 permeability and H2–CH4 mixture separation factor of MMMs with a MIL-88B(Fe) loading of 10% increased by 16% and 66%, respectively. In addition, the operation temperature has a significantly positive effect on the separation of a H2–CH4 mixture.