Revving Up a Designed Copper Catecholate Porous Organic Polymer for Its Potent Ethylene Adsorption than Ethane

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Cryogenic distillation is the traditional method for separating ethane (C2H6) and ethylene (C2H4).
• Porous organic polymers (POPs) offer tunable properties for gas separation applications.
• Developing selective adsorbents is crucial for efficient C2H4 purification.

Purpose of the Study:

• To develop a highly selective adsorbent for ethylene (C2H4) from ethane (C2H6)/ethylene (C2H4) mixtures.
• To investigate the use of copper(I)-coordinated POPs for enhanced C2H4 adsorption.
• To fine-tune pore size and π complexation for selective gas uptake.

Main Methods:

• Synthesis of a microporous copper(I)-coordinated POP (Cu@Di-POP).
• Adsorption experiments at various temperatures and pressures (273 K, 298 K, 323 K at 1 bar).
• Calculation of Ideal Adsorbed Solution Theory (IAST) selectivities.
• Density Functional Theory (DFT) for computational analysis of adsorption interactions.

Main Results:

• Cu@Di-POP demonstrated selective adsorption of C2H4 over C2H6.
• Adsorption capacities for C2H4 were 24.9, 18.9, and 13.4 cm3 g-1 at 273, 298, and 323 K, respectively.
• IAST selectivities for C2H4/C2H6 were 6.09, 5.60, and 4.13 at 273, 298, and 323 K, respectively.
• DFT studies revealed stronger π-electron interactions between Cu(I) and C2H4 (-37.23 kcal/mol) compared to C2H6 (-16.06 kcal/mol).

Conclusions:

• The Cu@Di-POP adsorbent exhibits excellent C2H4 selectivity due to optimized pore size and Cu(I)-π complexation.
• This material shows potential as a next-generation adsorbent for efficient C2H4/C2H6 separation.
• Computational insights support the experimental findings on selective adsorption mechanisms.