Structural and catalytic properties of V-SBA-15 for the vapor phase oxidation of diphenylmethane

Abstract

The influence of Si/V ratio of mesoporous V-SBA-15 on the structure and catalytic behavior has been investigated for the vapor phase oxidation of diphenylmethane (DPM) to benzophenone (BP) using CO 2 free air as oxidant under atmospheric pressure. The reaction conditions were optimized for a maximum conversion of DPM and selectivity for BP on V-SBA-15 (25). These catalysts were synthesized with different Si/V ratios of 10, 25, 50, 75 and 100 by the direct hydrothermal method under mild acidic conditions and characterized by using X-ray diffraction, ICP-OES, EDAX, DRUV-Vis, photoluminescence and transmission electron microscopy techniques. It was found that a large amount of vanadium is incorporated mainly in isolated tetrahedral environment with a terminal V=O bond. Under the optimized conditions, the activity of all the catalysts were compared and found that V-SBA-15 with Si/V = 25 ratio, exhibited the maximum activity. The difference in the catalytic activity is related to their physico-chemical properties.

Vanadium dispersion and catalytic activity of Pd/VOx/SBA-15 catalysts in the Wacker oxidation of ethylene

“…They found that the synthesized materials had larger surface area, higher dispersion, easy-to-reduce relative to the corresponding catalysts prepared by impregnation. The ordered mesoporous silica catalysts containing incorporated vanadia were active also in the vapor phase oxidation of diphenylmethane to benzophenone [25] and in the catalytic decomposition of dichloromethane to CO 2 [26].…”