Graphene-modified MIL-125-NH₂ mixed matrix membranes for efficient H₂ and CH₄ purification

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Technology

Background:

• Mixed matrix membranes (MMMs) are crucial for gas separation processes.
• Metal-organic frameworks (MOFs) and graphene nanosheets (GNs) offer promising properties for membrane enhancement.
• Efficient separation of methane (CH₄) and hydrogen (H₂) is vital for the purification sector.

Purpose of the Study:

• To investigate the performance of MMMs incorporating hybrid fillers (MIL-125-NH₂ and GNs).
• To enhance methane (CH₄) and hydrogen (H₂) separation efficiency for purification.
• To optimize fabrication parameters for improved membrane properties.

Main Methods:

• Fabrication of MMMs with varying ratios of MIL-125-NH₂ and GNs within a PES matrix.
• Physico-chemical characterization using SEM, XRD, FTIR, AFM, TGA, DTG, and BET.
• Gas permeation and selectivity measurements for CO₂, N₂, H₂, and CH₄ at different temperatures.

Main Results:

• Incorporating 0.05 wt% GNs into MOF/PES membranes significantly improved permeability (up to 370% for H₂).
• H₂/CO₂ and H₂/N₂ selectivities increased substantially (up to 236% and 230%, respectively).
• A hybrid filler of 10 wt% MIL-125-NH₂ and 0.05 wt% GNs is optimal for enhancing PES membrane performance.

Conclusions:

• Hybrid fillers of MIL-125-NH₂ and GNs effectively enhance MMMs for gas separation.
• The optimized MMMs demonstrate improved permeability and selectivity for CH₄ and H₂ purification.
• These findings suggest promising potential for advanced purification applications.