A novel method of synthesis and a new insight into the vanadium incorporation in three dimensional mesoporous KIT-6

Abstract

A nano-crystalline three-dimensional mesoporous KIT-6 and V-KIT-6 materials are synthesized through a new sol-gel method. The above-synthesized materials are characterized by various advanced techniques. The mesoporosity is confirmed by Low angle Powder x-ray diffraction, BET-surface area analysis, and Transmission electron microscopic analysis. The vanadium incorporation is established by Field emission scanning electron microscopy, Fourier transform Infrared spectroscopy, Raman spectroscopy, Electron spin resonance spectroscopy and Ultraviolet-visible diffuse reflectance spectroscopy. V-KIT-6 catalyzes cyclohexane oxidation using H2O2 and gives cyclohexanol and cyclohexanone as the products. The conversion (83% in 1 h) is remarkably higher in its class of compounds due to the presence of three-dimensional mesoporosity. The catalysts are found to be stable even after five successive cycles. A plausible vanadium species and catalytic reaction mechanism are also proposed.