Liquid phase hydroxylation of benzene to phenol over nano structure Cobalt (II) complex Encapsulated in Zeolite X

Liquid phase hydroxylation of benzene to phenol using H2O2 over nano structured cobalt(II) complex of pyridine-2,6-dicarboxylate encapsulated in the super cages of zeolite X (Co-PZ) catalysts was investigated in aqueous acetic acid (20/80, v/v).The structural properties of encapsulated cobalt(II) pyridine-2,6-dicarboxylate complex in the zeolite X cavities (Co-PZ) catalysts by flexible ligand method and its characterization using FTIR and XRD as well as transmission electron microscopy (TEM) and activity tests under various conditions were discussed. In extending the study of liquid-phase benzene hydroxylation, this paper reports the catalytic behaviors of Co-PZ for the liquid-phase hydroxylation of benzene under the various reaction conditions, with hydrogen peroxide and ascorbic acid used as the oxidant and the reducing reagent, respectively. The catalytic efficiency of Co-PZ in the hydroxylation of phenol was carried out in liquid phase. The effects of various factors that influence this catalytic reaction such as the solvent, reaction temperature, reaction time, catalyst amount and molar ratio of phenol to H2O2 were investigated intensively. Phenol was the sole product of the hydroxylation reaction. No other product in the liquid phase was detected by gas chromatography. Co-PZ catalysts were found to be highly effective catalysts for direct phenol synthesis in the liquid phase

Keywords:

Phenol , hydroxylation , Hydrogen peroxide , zeolite X , Encapsulated complex