The First Sulfate-Pillared Hybrid Ultramicroporous Material, SOFOUR-1-Zn, and Its Acetylene Capture Properties

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Hybrid ultramicroporous materials (HUMs) are modular crystalline structures with potential in gas separations.
• Existing HUM platforms show benchmark performance for industrial gas mixtures.
• There is a need for improved materials for selective acetylene (C2H2) and carbon dioxide (CO2) separation.

Purpose of the Study:

• To design and synthesize a novel sulfate-linked HUM for enhanced C2H2/CO2 separation.
• To investigate the material's gas sorption properties and separation capabilities.
• To establish a new benchmark for C2H2 and CO2 selectivity in HUMs.

Main Methods:

• Crystal engineering and gram-scale synthesis of a sulfate-linked HUM (SOFOUR-1-Zn).
• Characterization of the fsc topology coordination network using [Zn(tepb)(SO4)]n.
• Gas sorption analysis and dynamic column breakthrough studies for C2H2/CO2 mixtures.

Main Results:

• SOFOUR-1-Zn, a sulfate-linked HUM, was successfully synthesized.
• The material demonstrates selective binding of C2H2 over CO2 through specific O⋅⋅⋅HC interactions.
• A new benchmark for the heat of sorption difference (ΔQst = 24 kJ/mol) between C2H2 and CO2 was achieved.
• Fuel-grade C2H2 was obtained from trace or 1:1 C2H2/CO2 mixtures, outperforming SIFSIX-22-Zn.

Conclusions:

• Sulfate-linked HUMs represent a promising platform for selective gas separations.
• SOFOUR-1-Zn offers superior performance for C2H2/CO2 separation compared to existing materials.
• This work advances the development of advanced materials for industrial gas purification.