Fe-Based Microporous Metal-Organic Framework for C₂H₂/CO₂ Separation.

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Acetylene (C2H2) is a vital industrial chemical.
• CO2 contamination in C2H2 production presents a significant separation challenge.
• Efficient C2H2/CO2 separation is critical for industrial processes.

Purpose of the Study:

• To synthesize a novel metal-organic framework (MOF) for selective C2H2/CO2 separation.
• To investigate the adsorption properties and separation performance of the synthesized MOF.
• To elucidate the mechanism behind the selective C2H2 adsorption.

Main Methods:

• Synthesis of an iron-based MOF, STU-130, with a brn-1 net.
• Gas adsorption experiments (single-component and mixture).
• Computational simulations (DFT and GCMC).

Main Results:

• STU-130 exhibits a 1D channel decorated with uncoordinated carboxylate oxygen.
• High C2H2 uptake (106.8 cm3 g-1) and CO2 uptake (80.84 cm3 g-1).
• IAST-predicted selectivity of 4.2 for C2H2/CO2 mixtures and a 25 min g-1 elution time gap in breakthrough tests.

Conclusions:

• STU-130 demonstrates excellent C2H2/CO2 separation capability.
• Uncoordinated carboxyl oxygen atoms play a key role in selective C2H2 adsorption via C-H···O hydrogen bonds.
• This MOF offers a promising solution for purifying industrial acetylene streams.