Hydroxylation of phenol over rare earth exchanged iron pillared montmorillonites

Iron pillared montmorillonite prepared by partial hydrolysis method was exchanged with La, Ce and Th metal salts. The pillared montmorillonite showed considerable increase in basal spacing and surface area. EDAX showed presence of about 2% rare earth metals. 27Al and 29Si NMR spectra showed relaxation effects due to iron paramagnetic centres. The prepared systems are excellent catalysts for hydroxylation of phenol underlining the use of environmentally friendly clay catalysts for effective removal of pollutants. A detailed study of reaction variables suggests that oxidation of phenol increases with temperature and maximum conversion is obtained at 80 °C. Hydroquinone selectivity increases with phenol and solvent concentrations but decreases with time.