Hydrotalcite Load The Activity Of Titania Catalyst For Phenol Hydroxylation

The catechol and hydroquinone as the basic raw material industry, intermediate or additive have been widely applied, involving in pharmaceuticals, polymers, photographic, agrochemical materials.In this paper, the CuMgAlCO3 hydrotalcite-like precursor is stirringly prepared by microwave-assisted crystallization at 70℃at the reaction solution pH of 9-10. Then, the titanium dioxide is supported on catalyst by two kinds of methods such as intercalation and co-precipitation method. X-ray powder diffraction and IR analysis are performed for the precusors and the supported catalyst, which proves that the supported catalysts belong to the hydrotalcite structure.The activities of the supported catalysts on the hydroxylation of phenol are investigated. The experimental results show that the catalyst demonstrates a higher activity for the reaction. The effect of reaction conditions on the catalytic activity of phenol hydroxylation reaction is studied. Suitable hydroxylation conditions are optimized as following:reaction temperature of 60℃, reaction time of 60min, content of catalyst of 0.53g, the amount of 30% H2O2 of 24mL, phenol of 5.0g. Under the conditions, the conversion of phenol reaches to 89%. The catalytic process mechanism of hydroxylation of phenol is proposed.