Synthesis, characterization and catalytic activities of μ–oxo-bridged binuclear iron complexes encapsulated in SBA-15

Fe3+ bipyridine complexes were successfully anchored on the inner surface of the mesopores of SBA-15 and compared with those immobilized on the surface of SiO2. FT-IR, ESR, and XAFS measurements were used to characterize the structure of the formed μ–oxo-bridged binuclear Fe bipyridine complexes inside the mesopores of SBA-15, which were observed to be the active species for the oxidation of cyclohexane. Furthermore, binuclear Fe complexes anchored inside the mesopores of SBA-15 were found to show much higher activity than those anchored on the surface of SiO2. The effect of the presence of the SiOH groups on the surface of SiO2 on the selectivity for the oxidation of cyclohexane into cyclohexanone also was investigated.