Ionic Porous Aromatic Frameworks Embedding Polyoxometalates for Heterogeneous Catalysis.

Area of Science:

• Materials Science
• Porous Materials
• Catalysis

Background:

• Porous aromatic frameworks (PAFs) are stable, functional porous solids.
• Ionic PAFs (iPAFs) offer charged channels for adsorption, separation, and catalysis.
• Existing iPAFs often have low surface areas and complex synthesis.

Purpose of the Study:

• To develop an intuitive route for synthesizing iPAFs with high specific surface area.
• To explore the potential of these new materials for polyoxometalate loading and heterogeneous catalysis.

Main Methods:

• Synthesis of a multivariate ionic porous aromatic framework (MTV-iPAF, PAF-270) using readily available building units and a multivariable strategy.
• Characterization of PAF-270's hierarchical structure and high specific surface area.
• Evaluation of polyoxometalate loading capacity and catalytic performance of functionalized PAF-270.

Main Results:

• PAF-270 achieved the highest specific surface area among reported imidazolium-functionalized PAFs.
• High adsorption capacities (up to 50%) for HPW and V8 polyoxometalates were observed.
• HPW@PAF-270 and V8@PAF-270 showed excellent catalytic activity in oleic acid esterification and oxidative desulfurization, respectively.
• The materials demonstrated remarkable stability under varying temperature and pH conditions.

Conclusions:

• MTV-iPAFs, exemplified by PAF-270, offer a promising pathway to high-surface-area ionic porous materials.
• These materials exhibit significant potential for applications in catalysis and adsorption.
• The developed synthesis strategy and material properties underscore the versatility of iPAFs.