Ammoximation of cyclohexanone over a titanium silicate molecular sieve, TS-2

Abstract

The catalytic activity and selectivity of the titanium silicate molecular sieve, TS-2 (having ZSM-11 structure), in the ammoximation of cyclohexanone and other carbonyl compounds with H₂O₂ and NH₃ is reported in this paper. The studies were carried out at different temperatures and reactant concentrations and with different catalysts. TS-2 produces cyclohexanone oxime with high selectivities, while silicalite-2 and SiO₂ produce large quantities of the condensation product, peroxydicyclohexylamine. Similarly, when the concentrations of cyclohexanone and H₂O₂ are larger than that of NH₃, the formation of the byproducts is favoured. Based on the above results, mechanisms for the formation of cyclohexanone oxime and peroxydicyclohexylamine are presented.