Oxidation of organic compounds on TS-1 and Ti-Beta zeolites synthesized according to the "wetness impregnation method"

Abstract

Zeolites are crystalline microporous (alumino)-tectosilicates with a framework consisting of SiO4- and AlO4- tetrahedra, connected via the oxygen atoms at the corner points of the tetrahedron. The incorporation of metal atoms, other than aluminum in the framework of zeolites is also possible. This divided the zeolites in two groups: ion-exchanged zeolites and framework substituted zeolites. Framework substituted zeolites have different catalytic properties. The catalytic properties of zeolites, in which the Si in the framework is partly substituted by a metal ion like titanium, possess high potential in oxidation reactions or in Lewis acid catalyzed reactions. The first synthesis of silicalite TS-1 was achieved on 1983, and its unique catalytic activity in oxidation reactions with hydrogen peroxide, led to fast progress of investigation on heterogeneous catalytic oxidation and reveal a new possibility for economical and ecological attractive industrial production of some oxidized organic compounds. Ten years after that, the research group of Corma et. al., has published a direct synthesis of titanium containing materials with the framework of *BEA. Various synthesis procedures for preparation of TS-1 and Ti-Beta zeolites are described in the literature. In this thesis the TS-1 and Ti-Beta catalyst were synthesized with slight modifications according to a synthesis procedure called "wetness impregnation method". Different methods are used in order to characterize the zeolites samples synthesized in this work.Various classes of organic compounds were oxidized over TS-1 and Ti-Beta zeolites. Often the substrates could be considered as environmentally unfriendly , while the products of the oxidation reactions are environmentally friendly substances. Some of the catalytic oxidation processes, based on Ti-containing zeolites, can replace multi-step industrial syntheses.