Halogen-Substituted Zinc Porphyrin-Based Covalent Triazine Frameworks for Efficient Catalytic CO₂ Cycloaddition to...

Area of Science:

• Materials Science
• Catalysis
• Green Chemistry

Background:

• Cycloaddition of carbon dioxide (CO2) with aziridines offers a route to valuable industrial chemicals and CO2 mitigation.
• Conventional methods require harsh conditions (high temperature/pressure) and efficient catalysts are needed for milder processes.

Purpose of the Study:

• To synthesize and evaluate novel zinc porphyrin-based covalent triazine frameworks (ZnDBP-CTFs) as catalysts for CO2 cycloaddition to aziridines.
• To investigate the effect of halogen substitution on catalyst performance and material properties.

Main Methods:

• Synthesis of three ZnDBP-CTFs: ZnHDBP-CTF, ZnClDBP-CTF, and ZnBrDBP-CTF, with varying halogen substituents.
• Catalytic testing of ZnDBP-CTFs for CO2 cycloaddition to aziridines under mild conditions (1 atm CO2, 70°C).
• Characterization of material properties, including Lewis acidity and BET surface area.

Main Results:

• ZnDBP-CTFs exhibit tunable Lewis acidity and surface area influenced by halogen substituents.
• ZnBrDBP-CTF demonstrated exceptional catalytic activity (16.35 mol mol⁻¹ h⁻¹) under mild conditions.
• Performance is among the best reported for CO2 cycloaddition to aziridines.

Conclusions:

• Rational tuning of ZnDBP-CTFs by incorporating halogen atoms effectively modulates catalytic activity.
• Metalloporphyrin-based CTFs provide a robust platform for developing efficient catalysts for CO2 utilization.