Synthesis of aromatic ketones from aromatic compounds using vanadium-containing mesoporous silicates

Article abstract of DOI:10.1002/jccs.201100684

Aromatic ketones were synthesized from aromatic compounds via liquid-phase oxidation at 60 °C and 1 atm over vanadium-containing MCM-41 catalysts using a batch reactor. The catalysts were prepared by direct hydrothermal (4V-MCM-41) and wet impregnation (9V/MCM-41) methods. Their physico-chemical properties were determined with various characterization techniques. For the oxidations of all substrates in this work, 4 V-MCM-41 exhibits superior catalytic performance than 9 V/MCM-41 due to its larger values of unit cell parameter, BET surface area, and vanadium dispersion as well as stronger oxidation ability of vanadium-oxygen species. Apparently, the single site, isolated vanadium centers in 4V-MCM-41 possess much higher activity (based on the turnover number) than those containing more vanadium atoms in 9V/MCM-41. In addition, the substrate activities decrease in the order of diphenylmethane > fluorene > 9,10-dihydroanthracene > ethylbenzene ≥ 4-nitroethylbenzene, which are attributed to their distinct molecular structures.