Enhanced catalytic activity and catalyst stability in cyclohexanone ammoximation by introducing anatase into TS-1 zeolite

Abstract

Titanosilicate (TS-1) is widely used in the oxidations with hydrogen peroxide as a green oxidant. In the conventional synthesis of TS-1, it is easy to form anatase, which has been normally regarded as a catalyst for invalid decomposition of H2O2. Here, we have demonstrated that the anatase in TS-1 can enhance both activity and stability of the catalysts in cyclohexanone ammoximation. These features could be attributed to the interaction of anatase with ammonia, which not only favors ammonia absorption in the ammoximation evidenced by changing ammonia order to lower value, but also raise the corrosive resistance of zeolite framework by stronger anatase-ammonia interaction. This strategy has been successfully applied to the preparation of industrial TS-1 for cyclohexanone ammoximation at a scale of 300,000 tons per year, which might open a new opportunity for the industrial production of titanosilicate with enhanced alkaline resistance and catalytic reactivity in the future.