Defect-Engineered MOF-808-SO₄ as Efficient Solid Acid Catalysts for Esterification of n-Butyl Acetate

Area of Science:

• Materials Science
• Catalysis
• Green Chemistry

Background:

• Liquid acids pose corrosion and pollution risks.
• Traditional solid acids have performance limitations.
• Metal-Organic Frameworks (MOFs) offer tunable properties for catalysis.

Purpose of the Study:

• To develop novel sulfated MOF-808-SO4 catalysts.
• To address limitations of liquid and traditional solid acids.
• To utilize defect engineering for enhanced catalytic activity.

Main Methods:

• Ligand defect engineering in MOF-808 to create unsaturated sites.
• Sulfate grafting onto the MOF framework.
• Characterization using various techniques (e.g., NH3-TPD).
• Testing catalytic performance in esterification reactions.

Main Results:

• Sulfated MOF-808-SO4 catalysts were successfully synthesized with intact frameworks, high surface areas, and tunable porosity.
• Defect density directly correlated with the concentration and strength of acid sites.
• Optimized catalyst achieved ≥99% acetic acid conversion under mild conditions.
• Catalyst demonstrated excellent stability and recyclability over five cycles.

Conclusions:

• Defect engineering is an effective strategy for tuning acidity in MOF-based solid acids.
• Sulfated MOF-808-SO4 catalysts show superior performance for green esterification.
• This approach offers a sustainable alternative to conventional acid catalysts.