Catalysis and CO₂ Capture by Palladium-Incorporated Covalent Organic Frameworks

Area of Science:

• Materials Science
• Nanotechnology
• Catalysis

Background:

• Covalent Organic Frameworks (COFs) offer tunable porous structures for diverse applications.
• Triazine-based COFs are explored for their unique chemical properties and potential in catalysis and gas adsorption.
• Developing efficient catalytic systems and materials for carbon capture remains a critical challenge.

Purpose of the Study:

• To synthesize novel triazine-based imine and β-ketoenamine linked COFs.
• To functionalize these COFs with palladium nanoparticles for catalytic applications.
• To evaluate the catalytic performance and CO2 adsorption capabilities of the resulting materials.

Main Methods:

• Solvothermal synthesis of TAT-DHBD (1) and TAT-TFP (2) COFs using 1,3,5-tris-(4'-aminophenyl)triazine (TAT) and specific aldehydes.
• Post-synthetic modification to incorporate Pd(II) and subsequently reduce to Pd(0) nanoparticles within the COF matrices.
• Characterization using FTIR, solid-state 13C NMR, XPS, SEM, TEM, and BET surface area analysis.
• Evaluation of catalytic activity in Suzuki-Miyaura cross-coupling reactions and CO2 uptake measurements.

Main Results:

• Successful synthesis of TAT-DHBD and TAT-TFP COFs with significant meso- and microporosity.
• Uniform distribution of Pd(II) and Pd(0) nanoparticles within the COF structures confirmed by TEM.
• Pd-functionalized COFs (3-6) exhibited high activity and stability in Suzuki-Miyaura coupling, with minimal leaching over five cycles.
• COF 4 demonstrated notable CO2 uptake (11 wt% at 273 K and 7.5 wt% at 298 K at 1 bar).

Conclusions:

• Triazine-based COFs serve as effective platforms for anchoring palladium catalysts.
• The synthesized Pd-COF materials are highly efficient for Suzuki-Miyaura cross-coupling reactions.
• These COFs show promise for applications in catalysis and carbon dioxide capture due to their porous nature and functional sites.