Enhanced gas separation performance for H₂ purification using MIL-68(ln)-nh₂/PES mixed-matrix membranes

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Polyethersulfone (PES) membranes are crucial for gas separation but require enhanced permeability and selectivity.
• Sustainable and efficient gas separation technologies are in high demand for clean energy and industrial applications.

Purpose of the Study:

• To improve the gas separation performance of Polyethersulfone (PES) membranes by incorporating MIL-68(ln)-NH2 metal-organic frameworks (MOFs).
• To investigate the morphological, structural, thermal, and gas permeation properties of the novel MOF/PES mixed matrix membranes (MMMs).

Main Methods:

• A phase-inversion method was used to fabricate mixed matrix membranes (MMMs) incorporating 10 wt% MIL-68(ln)-NH2 into a PES matrix.
• Membrane characterization included SEM, AFM, BET, XRD, FTIR, and TGA-DTG.
• Gas permeation experiments were performed for CO2, N2, CH4, and H2 at temperatures ranging from 20-60 °C.

Main Results:

• The MOF/PES membranes exhibited increased porosity (9%), reduced roughness (87%), and smaller pore size (32%) compared to neat PES membranes.
• Significant improvements in morphology, crystallinity, and thermal stability (up to 22%) were observed.
• The MOF/PES membranes demonstrated high gas permeability and selectivity, with optimal performance for H2/N2 and H2/CO2 separations at specific temperatures.

Conclusions:

• The incorporation of MIL-68(ln)-NH2 MOFs significantly enhances the performance of PES membranes for gas separation.
• These MOF-based PES membranes show great potential for applications in gas separation, particularly for hydrogen purification.