Iron(III)-Modified Tungstophosphoric Acid Supported on Titania Catalyst: Synthesis, Characterization, and Friedel–Craft Acylation of <i>m</i>‑Xylene

The Friedel–Craft acylation of <i>m</i>-xylene with benzoyl chloride over iron-modified tungstophosphoric acid supported on titania was investigated. It was found that FeTPA/TiO₂ catalyst displayed excellent catalytic performance for this reaction. Furthermore, a series of catalysts were prepared and characterized by FT-IR, XRD, BET, NH₃-TPD, and Py-IR. The results indicated that both the Lewis acidity and the textural properties presented significant influences on their catalytic performance. Moreover, the influence of catalyst calcination temperature to the above reaction was also studied. The reaction parameters, including reaction temperature, catalyst dose, and molar ratio of <i>m</i>-xylene to benzoyl chloride, were optimized, and a 95.1% yield of 2,4-dimethylbenzophenone was obtained under optimal conditions. Finally, the kinetics of the benzoylation of <i>m</i>-xylene over 30% FeTPA/TiO₂ was established

Two-Dimensional Imine-Linked Covalent Organic Frameworks as a Platform for Selective Oxidation of Olefins

Two-dimensional imine-linked covalent organic frameworks with hydroxyl groups, <b>TAPT-DHTA-COF_HX</b> and <b>TAPT-DHTA-COF_DMF</b>, were respectively constructed by the condensation of 1,3,5-tris-(4-aminophenyl)­triazine and 2,5-dihydroxyl-terephthalaldehyde under solvothermal and reflux conditions. Both COFs possess excellent thermal stability and a similar eclipsed stacking structure verified by XRD patterns. However, <b>TAPT-DHTA-COF_HX</b> presented a larger surface area (2238 m²/g) and higher crystallinity than <b>TAPT-DHTA-COF_DMF</b>. Significantly, copper ions are efficiently incorporated into the pores of these two COFs via the coordination interaction with hydroxyl groups and imine linkers. The obtained copper-containing COFs (<b>Cu-COF_HX</b> and <b>Cu-COF_DMF</b>) were employed in the selective oxidation of styrene to benzaldehyde. <b>Cu-COF_HX</b> with superior surface area (1886 m²/g) and pore volume (1.11 cm³/g) exhibited excellent catalytic performance and recyclability. This strategy not only provides a convenient approach to design imine-linked 2D COFs with hydroxyl groups, but also develops their novel application for catalysis