Highly Robust {In₂}-Organic Framework for Efficiently Catalyzing CO₂ Cycloaddition and Knoevenagel Condensation

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Creating defects in metal-organic frameworks (MOFs) is a key strategy to enhance Lewis acidity and mass transfer.
• Defective MOFs offer improved catalytic performance due to optimized metal centers and pore structures.

Purpose of the Study:

• To synthesize a novel defective metal-organic framework (MOF) with enhanced catalytic properties.
• To investigate the catalytic activity of the defective MOF in CO2 conversion and Knoevenagel condensation.

Main Methods:

• Solvothermal synthesis of the NUC-65 MOF using indium clusters and H5BDCP ligand.
• Defect engineering of NUC-65 to NUC-65Br via ion exchange, solvent exchange, and vacuum drying.
• Catalytic performance evaluation using epichlorohydrin conversion and Knoevenagel condensation.

Main Results:

• The synthesized NUC-65 MOF features nanocaged voids and rectangular nanochannels.
• Defective NUC-65Br exhibits highly unsaturated metal centers, enhancing its catalytic activity.
• NUC-65Br achieved 99% conversion of epichlorohydrin with CO2 under mild conditions.
• NUC-65Br demonstrated excellent universal catalytic performance for various epoxides and high activity/selectivity in Knoevenagel condensation.

Conclusions:

• Defective MOFs, like NUC-65Br, offer a promising platform for designing advanced heterogeneous catalysts.
• The strategy of creating unsaturated metal centers in MOFs effectively boosts catalytic performance.
• This work provides insights into designing defect-engineered MOFs for diverse catalytic applications.