One Porous Metal-Organic Framework Containing Multinuclear Clusters and Functional Groups for Purification of...

Area of Science:

• Materials Science
• Chemical Engineering
• Adsorption Science

Background:

• Selective removal of trace acetylene (C₂H₂) from ethylene (C₂H₄) and carbon dioxide (CO₂) are critical industrial challenges.
• Existing methods often face limitations in efficiency and selectivity for these separations.

Purpose of the Study:

• To design and synthesize a novel hydroxy-functionalized metal-organic framework (MOF) for selective acetylene adsorption.
• To evaluate the MOF's performance in separating acetylene from ethylene and carbon dioxide.

Main Methods:

• Rational design and synthesis of a hydroxy-functionalized Zn(II)-based MOF, Zn-btb-OH, using a custom ligand (H₃btb-OH).
• Characterization of the MOF's structure and adsorption properties.
• Adsorption experiments, Ideal Adsorbed Solution Theory (IAST) calculations, dynamic breakthrough tests, and Grand Canonical Monte Carlo (GCMC) simulations.

Main Results:

• Zn-btb-OH exhibits a unique interwoven architecture with open channels and cage-like cavities.
• High acetylene adsorption capacity (60.1 cm³ g^-1) and preferential adsorption for C₂H₂ over C₂H₄ and CO₂.
• IAST selectivity values of 2.2 for C₂H₂/C₂H₄ and 4.4 for C₂H₂/CO₂; successful dynamic separation demonstrated.

Conclusions:

• The synthesized Zn-btb-OH MOF demonstrates excellent performance for selective acetylene removal and separation.
• Specific host-guest interactions, including C-H···π and C-H···O contacts, are responsible for the high acetylene affinity.
• Zn-btb-OH shows significant potential for industrial applications in gas purification and separation.