Selective liquid‐phase oxidation of toluene with molecular oxygen catalyzed by Mn‐TiO 2 under solvent‐free conditions

Abstract In this paper, we reported the preparation, characterization, and catalytic performance of TiO 2 doped with Mn for the selective oxidation of toluene to benzyl alcohol and benzaldehyde without any solvent. The structure of the catalyst was determined by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), nitrogen adsorption–desorption analysis (Brunauer–Emmet–Teller [BET]), scanning electron microscope (SEM), transmission electron microscope (TEM), and mapping. The results demonstrated that the catalytic properties of Mn‐TiO 2 were higher than those of pure Mn 3 O 4 and TiO 2 . The effects of reaction temperature, reaction time, oxygen pressure, and the amount of catalyst were studied. Under the optimal conditions, Mn‐TiO 2 could afford 6.4% toluene conversion at a combined benzyl alcohol/benzaldehyde selectivity of 58.6%. Moreover, the catalyst can be repeated in the experiment for five times without significant loss of activity.