Aerobic Oxidation Of Fluorene To Fluorenone Over Copper-Doped Co3o4 With A High Specific Surface Area

Copper-doped Co3O4 with a high specific surface area has been prepared by using mesoporous silica KIT-6 as a hard template, which showed exceptional catalytic performance (99% conversion of fluorene and 99% selectivity of fluorenone) for catalytic oxidation of fluorene to fluorenone using molecular oxygen as the oxidant in the absence of a radical initiator or other cocatalysts. Characterization results of N-2 adsorption-desorption, X-ray diffraction, and transmission electron microscopy of the samples revealed the ordered mesoporous structure and increased specific surface area. X-ray photoelectron spectroscopy and O-2 temperature-programmed desorption results showed the increased surface cobalt, Co-3(+)/Co2+ ratio, and oxygen species. The H-2 temperature-programmed reduction also indicated that the redox ability could be improved by doped copper in Co3O4, which all facilitated the aerobic oxidation reaction.