Phenol hydroxylation using Fe/Al-MCM-41 catalysts

Fe loaded Al-MCM-41, (Si/Al = 25, 50, 75 and 100) catalysts were synthesized by hydrothermal method and characterized by the XRD, BET (surface area), FT-IR, and UV- vis and Mossbauer techniques. The liquid phase hydroxylation of phenol with hydrogen peroxide was studied and exclusive formation of dihydroxybenzene was observed. The phenol conversion was found to be almost same at various reaction temperatures viz 40, 60 and 80 degrees C, but at room temperature only about 30% conversion was recorded. The activity followed the order Fe/Al-MCM-41 (25) > Fe/Al-MCM-41(50) > Fe/Al-MCM-41 (75) > Fe/Al-MCM-41 (100) which was also the order of acidity. Effects of Fe content in Fe/Al-MCM-41 catalysts, solvent, phenol/H2O2 mole ratio on phenol conversion was examined. The reaction was also carried out over 10% iron loaded mordenite and the results are compared.