Chemically Modified HKUST-1(Cu) for Gas Adsorption and Separation: Mixed-Metal and Hierarchical Porosity

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Metal-organic frameworks (MOFs) are porous materials with tunable properties.
• HKUST-1 is a well-known MOF, but its performance for specific gas separations can be improved.
• Acid gas separation, particularly CO2 and SO2, is crucial for environmental remediation and industrial processes.

Purpose of the Study:

• To systematically modify the archetypical HKUST-1 MOF.
• To introduce bimetallic centers and create hierarchical defects.
• To enhance the MOF's affinity and selectivity for acid gases like CO2 and SO2.

Main Methods:

• Systematic modification of organic and inorganic building blocks of HKUST-1.
• Creation of bimetallic hierarchical structures and network defects.
• Gas adsorption and selectivity measurements for CO2 and SO2 mixtures.

Main Results:

• Modified MOFs exhibited altered affinities for acid gases.
• Bimetallic sites primarily influenced CO2 adsorption.
• Hierarchical structures significantly increased SO2 uptake capacity.
• HH-Cu100 material achieved a high SO2/CO2 selectivity of 3420 at 298 K.

Conclusions:

• Tailoring MOF structures through bimetallic incorporation and defect engineering enhances acid gas separation.
• Hierarchical MOFs offer improved performance for SO2/CO2 mixtures near room temperature.
• The synthesized HH-Cu100 MOF demonstrates potential as a benchmark material for selective SO2 capture.