Highly efficient and recyclable basic mesoporous zeolite catalyzed condensation, hydroxylation, and cycloaddition...

Area of Science:

• Materials Science
• Catalysis
• Organic Chemistry

Background:

• Zeolites, particularly ZSM-5, are crucial in catalysis.
• Developing mesoporous zeolites enhances catalytic performance.
• Introducing basic sites can tailor zeolite reactivity for specific transformations.

Purpose of the Study:

• To synthesize crystalline mesoporous ZSM-5 with basic properties.
• To characterize the synthesized material thoroughly.
• To evaluate its catalytic efficacy in diverse organic syntheses and assess recyclability.

Main Methods:

• Synthesis of mesoporous ZSM-5 using a specific structure directing agent.
• Post-synthesis treatment with ammonium hydroxide (NH4OH) to impart basicity.
• Characterization using X-ray diffraction (XRD), N2-adsorption, electron microscopy, and temperature-programmed desorption (TPD).
• Catalytic evaluation in Knoevenagel condensation, benzamide hydroxylation, multi-component reactions, and CO2 cycloaddition.

Main Results:

• Successful synthesis of basic mesoporous ZSM-5.
• Comprehensive characterization confirmed crystalline mesoporous structure and basic sites.
• High catalytic activity observed in synthesizing substituted styrenes, carbinolamides, naphthopyrans, and cyclic carbonates.
• The catalyst maintained significant activity after five recycling iterations.

Conclusions:

• The developed basic mesoporous ZSM-5 is a highly effective and recyclable heterogeneous catalyst.
• Its tailored properties enable diverse organic transformations with high efficiency.
• This catalyst presents a promising alternative for sustainable chemical synthesis.