Engineering Pore Chemistry and Environment in Robust Metal-Organic Frameworks for One-Step C₂H₄ Purification from...

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Efficient separation of ethylene (C2H4) from acetylene (C2H2) and ethane (C2H6) is crucial for the petrochemical industry.
• Current one-step separation strategies face significant challenges in achieving high purity.

Purpose of the Study:

• To design and synthesize novel metal-organic frameworks (MOFs) for the selective, one-step purification of ethylene from ternary mixtures.
• To investigate the impact of pore engineering and Lewis basic sites on separation performance.

Main Methods:

• Utilized reticular chemistry and pore engineering to modify isomorphic Zn-MOFs.
• Adjusted pore size, shape, and incorporated Lewis basic sites by altering functional groups.
• Conducted adsorption and multiple-component dynamic breakthrough experiments.
• Performed theoretical calculations to understand molecular interactions.

Main Results:

• Developed ZnatzOAC, a MOF with optimized irregular pores and Lewis basic sites, showing enhanced affinity for C2H2 and C2H6 over C2H4.
• Achieved high C2H2 sorption (43 cm3 g-1) and packing density (266.9 g L-1) in ZnatzOAC.
• Demonstrated exceptional separation performance, yielding polymer-grade C2H4 purity of 99.95% from ternary mixtures.
• Theoretical calculations confirmed the role of amino groups in modifying pore environment for selective adsorption.

Conclusions:

• The engineered MOF, ZnatzOAC, provides an effective solution for one-step ethylene purification.
• Reticular chemistry and pore engineering are powerful tools for designing advanced separation materials.
• The study highlights the potential of MOFs in addressing critical industrial separation challenges.