Highly reactive magnetite covered with islands of carbon: oxidation of N and S-containing compounds in a biphasic system

Abstract

In this work a series of magnetite were prepared by impregnating of natural goethite (limonite) with glycerol before thermal treatment under N2 flow at 300, 400 and 500 °C. The formation of carbon spots (island) over magnetite was found. The magnetite was found to be the main phase after treatment at 400 and 500 °C with high content of Fe2+, which is the active specie in a Fenton like system. Furthermore, iron oxide particles with magnetic and amphiphilic properties were formed, which are interesting for using as a catalyst in refineries. All materials presented high catalytic activities for oxidation of quinoline and dibenzothiophene in a biphasic reaction system (water/toluene).