Development Of TS-1 Catalyst For The Ammoximation Of Cyclohexanone To Cyclohexanone Oxime

The bulk chemical cyclohexanone oxime is a key intermediate for the manufacture of e-caprolactam (CPL), a starting material for Nylon-6 synthesis. With the increasing demand of CPL, the production of cyclohexanone oxime continuously grows. A traditional method for the synthesis of cyclohexanone oxime is the so-called cyclohexanone-hydroxylamine route, in which the toxic hydroxylamine and corrosive sulfuric acid are used in the production process, leading to environmental problems. Later, the Italian company EniChem S.p.A developed TS-1 used as the catalyst in the ammoximation of cyclohexanone, which is more effective and cleaner, compared to the conventional process. However, in the reported synthesis methods, there are extra-framework Ti-species available or low quadridentate-framework Ti-species contents in the synthesized TS-1 samples. Additionally, the used template tetrapropylammonium hydroxide (TPAOH) for the synthesis is rather expensive, leading to high costs of TS-1 synthesis.The current research aims to develop synthesis methods, in which the cheap template was used, instead of the expensive TPAOH, to reduce the costs of TS-1 synthesis, and TS-1 samples with only framework Ti-species and uniform and controllable crystal size were synthesized. Then the synthesized samples were characterized by various techniques such as XRD, SEM, UV-vis, FT-IR, and N2 adsorption-desorption. Furthermore, the catalytic properties of the TS-1 catalysts were evaluated in the ammoximation of cyclohexanone. The main results are summarized as follows:1. The cheaper template n-butylamine (n-B A), partially instead of TPAOH, was used to synthesize TS-1, leading to lower costs of the resultant TS-1.2. TS-1 samples with only framework Ti-species and uniform crystal sizes smaller than 500nm were successfully synthesized via optimization of the synthesis process and conditions. The synthesized TS-1 catalysts show some excellent catalytic properties in the ammoximation of cyclohexanone.The novelty of the thesis:TS-1 samples with only framework Ti-species were synthesized via optimization of the synthesis conditions, in which the synthesis process is simpler and the synthesis period is shorter. In addition, the synthesized TS-1 catalysts show some better catalytic properties in the ammoximation of cyclohexanone, compared to ones industrially used.