Oxidation of benzyl alcohol through eco-friendly processes using Fe-doped cryptomelane catalysts

摘要

Due to the convenience of catalyst separation and solvent-free conditions, gas-phase oxidation of benzyl alcoholin particular to-benzaldehyde reaction is more attractive method for industrial applications. In this respect it is environmentally and scientifically important to develop a low cost, energy-saving, and green approach for benzyl alcohol oxidation reaction, as an alternative to conventional liquid phase aerobic oxidation. Herein, a facile method for enhancing the catalytic activity of K-OMS-2 for benzyl alcohol-to-benzaldehyde oxidation by adding a small amount of Fe-2(SO4)(3) to the mixture of KMnO4 & MnSO4 with Fe/Mn = 0, 0.03, 0.06, 0.08 and 0.10 was report. The physico-chemical characteristics of the prepared samples were studied by using powder XRD, UV-VIS, N-2-physisorption, HR-TEM, FT-IR and H-2-TPR techniques. The influence of the different iron amounts on the catalytic performance of the prepared xFe-OMS-2 samples at different reaction temperature (250 degrees C-450 degrees C) using air as an oxidant carrier gas was investigated. H-2-TPR results confirmed that iron doping facilities the Mn4+<--> Mn3+ redox cycle for providing oxygen species that are necessary for benzyl alcohol oxidation reaction. Also the lower reducibility, Small particle sizes with higher iron species dispersion within the OMS-2 framework matrix also had a great influence on the catalytic activity effectiveness of the tested samples.