Immobilization of manganoporphyrin on a novel polymeric support and catalytic oxidation characteristic of supported catalyst

Abstract

AbstractMonomer glycidyl methacrylate (GMA) was grafted on silica gel particles in the manner of “grafting from,” and the grafted particles PGMA/SiO2 was prepared. The grafted particles PGMA/SiO2 is a kind of novel support for the immobilization of metalloporphyrin catalysts. In the presence of basic catalysts, the ring‐opening reaction of the epoxy groups of the grafted PGMA occurred and the bonding of meso‐tetra (4‐hydroxylphenyl) porphyrin (THPP) on the particles PGMA/SiO2 was realized, resulting in the bonded particles HPP‐PGMA/SiO2. Subsequently, the metallation of the bonded particles HPP‐PGMA/SiO2 was carried out via the coordination reaction between HPP‐PGMA/SiO2 and manganese salt, resulting in the supported manganoporphyrin (MnP) catalyst MnP‐PGMA/SiO2. The supported catalyst was used in the catalytic oxidation of ethyl benzene into acetophenone by molecular oxygen. In this article, the effects of various factors such as the species and amount of the catalyst on the bonding process of THPP were studied because of the importance of the bonding reaction of THPP in the preparation of the catalyst MnP‐PGMA/SiO2. Finally, the catalytic performance of MnP‐PGMA/SiO2 in the catalytic oxidation process of ethyl benzene was investigated. The experimental results show that triethylamine is a suitable catalyst for the bonding of THPP on the grafted particles PGMA/SiO2 and for the forming of MnP‐PGMA/SiO2. The supported catalyst MnP‐PGMA/SiO2 can effectively activate molecular oxygen, and obviously catalyze the oxidation process of ethyl benzene to acetophenone by molecular oxygen. It was found that the immobilization density of MnP on MnP‐PGMA/SiO2 has a great effect on the catalytic activity of the catalyst. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009