High Selectivity of Supported Oxo-trinuclear Compounds in Styrene Epoxidation

The aim of this study was to establish the ability of four oxo-trinuclear coordinative compounds to act as catalysts in the oxidation of side double bond of styrene by hydrogen peroxide. In order to characterize the functionalized silica and the complexes immobilized on silica matrix, the adsorption/desorption isotherms and the thermograms were plotted. The obtained results revealed that these compounds are thermically stable up to 160 °C and have high surface area, which makes them good candidates for catalytic tests. To further monitor the catalytic activity of the compounds of interest and to identify the products of styrene oxidation reaction was used the GC-MS analysis. In the case of oxo-trinuclear iron compound, a 45% conversion rate of styrene into final products was achieved in 24 h. The data analysis also highlighted a good selectivity for benzoic aldehyde, another by-product (benzoic acid) occurring only after a longer time of reaction (24 h). The turnover numbers (TON) were also calculated for the four newly synthesized compounds.