Metal-Organic Framework Based Hydrogen-Bonding Nanotrap for Efficient Acetylene Storage and Separation

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Acetylene (C2H2) purification requires efficient carbon dioxide (CO2) removal, a challenge due to similar molecular properties.
• Existing methods struggle with the adsorption capacity-selectivity tradeoff for C2H2/CO2 separation.

Purpose of the Study:

• To develop a novel strategy for enhanced C2H2/CO2 separation using engineered metal-organic frameworks (MOFs).
• To investigate the role of hydrogen-bonding nanotraps in selective gas adsorption and separation.

Main Methods:

• Synthesis and characterization of three isostructural MOFs (MIL-160, CAU-10H, CAU-23) with tailored pore surfaces.
• Gas adsorption/desorption experiments under ambient conditions.
• Breakthrough experiments, computational modeling, and in situ FT-IR spectroscopy to elucidate adsorption mechanisms.

Main Results:

• MIL-160 exhibits an ultrahigh C2H2 storage capacity (191 cm3 g-1) and significantly lower CO2 uptake (90 cm3 g-1).
• MIL-160 demonstrates superior C2H2/CO2 separation performance, setting new benchmarks for separation potential and C2H2 productivity.
• Host-guest hydrogen-bonding interactions between MIL-160's nanotraps and C2H2 are identified as key to selective adsorption.

Conclusions:

• Regulating hydrogen-bonding nanotraps on MOF pore surfaces is an effective strategy for challenging C2H2/CO2 separation.
• MIL-160 represents a highly promising material for industrial acetylene purification.
• This approach offers a new pathway for overcoming limitations in selective gas separation.