A High-Performance N₂-Selective MXene Membrane with Double Selectivity Mechanism for N₂/CH₄ Separation.

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Technology

Background:

• Membrane-based separation is crucial for purifying unconventional natural gas, primarily for nitrogen/methane (N₂/CH₄) separation.
• Current N₂-selective membranes predominantly rely on a single diffusivity-selectivity mechanism, limiting performance.
• There is a need for advanced membranes with enhanced separation efficiency and economic viability.

Purpose of the Study:

• To develop 2D lamellar MXene membranes with a dual selectivity mechanism for improved N₂/CH₄ separation.
• To overcome the limitations of single-mechanism membranes by introducing specific interactions for enhanced N₂ permeation.
• To investigate the potential of MXene membranes in unconventional natural gas purification.

Main Methods:

• Fabrication of 2D lamellar MXene membranes.
• Introduction of unsaturated metal sites into the MXene structure to create specific interactions with N₂ molecules.
• Evaluation of membrane performance using N₂/CH₄ gas mixture separation tests.

Main Results:

• The developed MXene membranes exhibit a dual selectivity mechanism, enhancing both N₂ permeance and N₂/CH₄ selectivity.
• Achieved an impressive N₂ permeance of 344 GPU.
• Demonstrated a high N₂/CH₄ selectivity of 13.76.

Conclusions:

• The collaboration of the dual selectivity mechanism in MXene membranes offers a novel approach for N₂ removal and CH₄ purification.
• These findings provide a new avenue for developing advanced N₂-selective membranes.
• The study broadens the application prospects of membrane separation technology in unconventional natural gas purification.