Acidic ionic liquid based UiO-67 type MOFs: a stable and efficient heterogeneous catalyst for esterification

Area of Science:

• Materials Science
• Catalysis
• Green Chemistry

Background:

• Developing efficient and reusable heterogeneous acid catalysts is crucial for sustainable chemical synthesis.
• Metal-organic frameworks (MOFs) offer tunable structures for catalyst design.
• Ionic liquids possess unique properties that can enhance catalytic performance.

Purpose of the Study:

• To synthesize novel acidic ionic liquid-based UiO-67 MOFs.
• To investigate their structural and chemical properties.
• To evaluate their catalytic performance in esterification reactions.

Main Methods:

• Facile synthesis of UiO-67-bpy MOFs incorporating Brønsted acids (H2SO4, CF3SO3H, hifpOSO3H).
• Characterization using XRD, SEM, FT-IR, EA, TGA, and N2 adsorption-desorption.
• Catalytic evaluation via esterification of acetic acid with isooctyl alcohol.

Main Results:

• UiO-67-based acidic ionic liquid catalysts (UiO-67-HSO4, UiO-67-CF3SO3, UiO-67-hifpOSO3) were successfully synthesized.
• High surface area was maintained with uniformly dispersed acidic groups.
• UiO-67-CF3SO3 achieved 98.6% isooctyl alcohol conversion, demonstrating high catalytic activity.
• Catalysts exhibited excellent stability and reusability over five cycles with minimal leaching.

Conclusions:

• A facile strategy for creating heterogeneous acidic ionic liquid catalysts based on UiO-67 MOFs was established.
• The synthesized catalysts demonstrate significant potential for applications in acid catalysis.
• This work provides a pathway for designing isolated, well-defined acidic sites in MOFs for enhanced catalytic processes.