Polymer-Derived Amorphous Aluminosilicate Nanomembranes for H₂ Purification.

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Aluminosilicate zeolite membranes are effective for hydrogen separation but difficult to produce at scale.
• Current fabrication methods for zeolite membranes are costly and complex, limiting practical applications.

Purpose of the Study:

• To develop a scalable and cost-effective method for producing advanced nanomembranes for gas separation.
• To combine the processability of polymers with the separation capabilities of aluminosilicates.

Main Methods:

• Fabrication of thin-film composite membranes using polydimethylsiloxane.
• Surface modification via oxygen plasma treatment to create polyorganosilica (POSi).
• Few-cycle atomic layer deposition (ALD) using trimethylaluminum and water vapor to form amorphous aluminosilicates.

Main Results:

• Achieved few-nanometer amorphous aluminosilicate layers with enhanced size-sieving properties.
• Significantly increased H2/CO2 selectivity (39 to 200) and H2/CH4 selectivity (190 to 500) after three-cycle ALD.
• Maintained high H2 permeance (210 GPU at 150 °C), outperforming existing state-of-the-art membranes.

Conclusions:

• The developed two-step process enables rapid and scalable manufacturing of amorphous aluminosilicate nanolayers.
• These nanomembranes offer superior performance for hydrogen/light gas separation.
• The technology holds potential for catalysis and adsorption applications.