High-Entropy Metal-Organic Frameworks (HEMOFs): A New Frontier in Materials Design for CO₂ Utilization

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• High-entropy materials (HEMs) show promise for chemical transformations like CO2 utilization.
• Traditional HEM catalysts lack porosity, limiting their active sites to the surface.
• Designing porous HEMs can enhance reactivity while retaining high configurational entropy.

Purpose of the Study:

• To design and synthesize novel porous high-entropy metal-organic frameworks (HEMOFs) from polynuclear metal clusters.
• To investigate the catalytic activity of HEMOFs for CO2 fixation.
• To understand the structure-property relationships in HEMOFs using experimental and theoretical methods.

Main Methods:

• Synergistic experimental, analytical, and theoretical approach.
• Synthesis of HEMOFs incorporating up to 15 distinct metals.
• High-resolution scanning transmission electron microscopy (STEM) for observing metal mixing.
• Density functional theory (DFT) studies for electronic structure analysis.

Main Results:

• Successfully synthesized the first HEMOFs derived from polynuclear metal clusters.
• Achieved homogenous metal mixing within individual clusters, confirmed by HR-STEM.
• Demonstrated high activity for CO2 fixation under mild conditions with short reaction times.
• HEMOFs outperformed existing heterogeneous catalysts in CO2 utilization.
• DFT studies revealed the sensitivity of electronic structures to metal composition in heterometallic clusters.

Conclusions:

• This work introduces a novel class of porous HEMs (HEMOFs) with significant potential for CO2 utilization.
• The findings advance HEMOF materials design and offer new avenues for multifunctional materials.
• The developed HEMOFs provide a promising platform for exploring advanced catalytic applications.