SELECTIVE CATALYTIC-OXIDATION OF ANILINE TO AZOXYBENZENE OVER TITANIUM SILICATE MOLECULAR-SIEVES

The oxidation of aniline using aqueous H2O2 and titanium silicates, TS -1 and TS-2 as catalysts was carried out in a batch reactor in the tem perature range 333-353 K. TS-1 catalyzes aniline selectively to azoxyb enzene and is superior to TS-2. The influence of different solvents, c oncentration of H2O2 and the catalyst in the reaction mixture on the c onversion and product distribution has been studied. Acetonitrile is a suitable solvent in this reaction, while acetone is not. For the TS-1 catalyzed oxidation reaction, t-butyl hydroperoxide is not a suitable oxidant. At optimum conditions, a H2O2 efficiency of about 100% for a niline conversion is obtained with a selectivity of 97% to azoxybenzen e in the product.