Immobilization of some Transition Metal Complexes on Silica gel Surface and their Catalytic Activity

Abstract

The present work includes the investigation of the heterogeneous catalytic activity of the transition metal imidazole complexes on the decomposition of hydrogen peroxide. Among these metal ions are; copper(Il), cobalt(II) and manganese(II). These metal complexes are immobilized on some support surfaces such as; silica-gel, alumina and silica­ alumina by diverse methods. The role of immobilization method, the stoichiometry of the metal complex, the type of surfaces and some other parameters on the activity and the kinetics of the decomposition reaction are investigated.

The immobilization of the metal complexes on the support surfaces are carried out either by adsorption of the complex or by the modification of the surface with the coupling agent (3-chloropropyltrimethoxysilane) followed by addition of imidazole and metal ions. The complex immobilized by modification of the surface revealed only 1 : 4 stoichiometry, while in the case of the adsorption method, different stoichiometries have been prepared.