Fe-Supported SBA-16 Type Cagelike Mesoporous Silica with Enhanced Catalytic Activity for Direct Hydroxylation of Benzene to Phenol

Abstract

In this work, an Fe-supported cagelike mesoporous silica type SBA-16 catalyst (Fe/SBA-16) was successfully synthesized using iron nitrate as the precursor through a simple impregnation method. Results of X-ray diffraction, N2 adsorption–desorption, transmission electron microscopy, and elemental mapping analysis showed that the mesoporous structure of the support was retained during catalyst preparation and that iron nanoparticles were dispersed on the SBA-16 surface. Moreover, ultraviolet–visible and X-ray photoelectron spectroscopic studies revealed that the iron­(III) oxidation state was dominant in the Fe-supported cagelike mesoporous silica. It was found that the Fe/SBA-16 was an appropriate catalyst for the benzene hydroxylation to phenol using H2O2 as the oxidant. The effects on the catalytic performance of operating parameters such as the amount of H2O2, reaction temperature, reaction time, and catalyst dosage were investigated. Under the optimized conditions, 11.7% phenol yield and 96.4% selectivity to phenol were obtained; in addition, the catalyst could be recycled at least three times.

Preparation of Fe@Cu‐BDC and its catalytic performance for benzene hydroxylation

“…Table 3 presents the catalytic activity of the various catalysts for benzene hydroxylation at 60°C. The content of catalysts was set at 150 mg. Jourshabani et al [39] explored an Fe-supported SBA-16 type catalyst used in the direct synthesis of phenol from benzene. They discussed the impact of molar ratio of catalyst to benzene on the yield of phenol in the range 0.011 to 0.027.…”

Oriented Decoration in Metal-Functionalized Ordered Mesoporous Silicas and Their Catalytic Applications in the Oxidation of Aromatic Compounds

“…Therefore, the involved direct hydroxylation of benzene has been intensively studied based on the transition metal modified mesoporous silica. Mohammadi et al [116] reported the Fe examined reaction. The advanced 3D structure facilitates mass transfer and the number of collisions between nickel species and reaction intermediates are increased during the reaction.…”

“…Therefore, the involved direct hydroxylation of benzene has been intensively studied based on the transition metal modified mesoporous silica. Mohammadi et al [116] reported the Fe modified SBA-16 for the direct hydroxylation of benzene with 11.7% conversion and 96.4% selectivity towards phenol, and Figure 14 shows a reaction mechanism of the catalytic benzene hydroxylation by H 2 O 2 in the presence of Fe/SBA-16. However, this result seems to be undesirable compared to other functional mesoporous catalysts.…”

“…The catalytic properties of different catalysts on benzene oxidation are shown in Table 1. Reprinted with permission from [116], Copyright 2016, American Chemical Society.…”

“…Considerable endeavors have been devoted to the exploration of the enhancement of catalytic properties. Obviously, catalytic conversion of styrene over those catalysts is definitively affected by catalytic metal types especially for metal Ni, Ti, Ce, Co, Reprinted with permission from [116], Copyright 2016, American Chemical Society.…”