Arraying Shape-Persistent Molecular Alkynyl Trap into Highly Porous and Robust Zirconium Metal-Organic Framework for...

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Adsorptive separation of propyne/propylene (C3H4/C3H6) is crucial for energy-efficient production of polymer-grade C3H6.
• Current adsorbents, like ultramicroporous metal-organic frameworks (MOFs), often have limitations in C3H4 uptake capacity and adsorption enthalpy.

Purpose of the Study:

• To develop a novel, highly porous, and robust zirconium metal-organic framework (MOF) for efficient C3H4/C3H6 separation.
• To investigate the adsorption properties and separation performance of the new MOF, SJTU-520.

Main Methods:

• Synthesis and characterization of a novel zirconium MOF, SJTU-520, incorporating cyclotetrabenzoin-derived molecular arrays.
• Adsorption isotherm measurements and breakthrough experiments to evaluate C3H4/C3H6 separation performance at ambient conditions.
• Computational simulations to elucidate the mechanism of selective C3H4 adsorption.

Main Results:

• SJTU-520 exhibits a high surface area (3650 m²/g) and superior C3H4 uptake capacity (6.1-fold increase compared to related materials).
• Achieved a record high C3H4/C3H6 uptake ratio and efficient separation at 1 bar and 298 K.
• Demonstrated excellent recyclability and high productivity of polymer-grade C3H6 from a 10/90 C3H4/C3H6 mixture via breakthrough experiments.
• Computational studies revealed preferential π-π interactions between the MOF's cyclotetrabenzoin macrocycle and C3H4.

Conclusions:

• SJTU-520 represents a significant advancement in MOF-based adsorbents for C3H4/C3H6 separation.
• The reticulation of intrinsically functional organic scaffolds into porous frameworks is a powerful strategy for designing tailored materials.
• This work paves the way for energy-efficient industrial separation processes.