Heterogeneous catalyst Mn(salicylaldimine) complex covalently bonded to α-titanium phosphate: Synthesis, characterization and catalytic activity for oxidation of cyclohexane

Abstract

A new heterogeneous catalyst, Mn(salicylaldimine) complex covalently bonded to α-titanium phosphate has been synthesized by in situ method and characterized by BET surface area, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, Fourier transform infrared spectra, X-ray photoelectron spectroscopy and inductively coupled plasma atomic emission spectroscopy. The catalytic activity of α-TiP.Mn(salicylaldimine) is studied for the liquid phase oxidation of cyclohexane using tert-butylhydroperoxide as an oxidant under solvent-free condition. In the oxidation reaction, cyclohexane is oxidized to cyclohexanol, cyclohexanone and some unidentified products. A maximum conversion (14.75%) of cyclohexane with 91.70% selectivity of KA-oil is obtained at 353 K after 6 h of reaction time. The catalyst can be reused for four cycles without significant loss of catalytic activity.