Preparation and characterization of mesoporous silica supported cobalt oxide as a catalyst for the oxidation of cyclohexanol

Cobalt oxide catalysts supported on mesoporous silica SBA-15 were prepared by the “two-solvent” method and compared with analogous catalysts prepared by the more conventional methods of impregnation and adsorption. Cobalt nitrate was used as the precursor. The catalysts were characterized by N2 adsorption–desorption, XRD, FTIR, XPS, TPR, ICP-MS, TEM and DR UV–vis. Their activity for the oxidation of cyclohexanol was determined by GC and GC–MS. The effect of metal loading on the morphology and catalytic activity of the catalysts was investigated. The catalyst with the lowest cobalt content exhibited the highest catalytic activity for cyclohexanol oxidation due to the better accessibility of the reactants to the catalytic sites.

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► Cobalt nitrate used as a precursor for cobalt oxide supported on SBA-15.
► Co3O4 spinel formed in patches within mesoporous silica channels.
► Patches developed as nanorods with lengths proportional to cobalt loading.
► Cobalt catalysts were active for liquid phase oxidation of cyclohexanol.
► Lowest cobalt loading showed highest activity suggesting accessibility limitations.