Synthesis, characterization and catalytic oxidation activity of zirconium doped K-OMS-2 type manganese oxide materials

Abstract

Zirconium doped manganese oxide OMS-2 materials have been synthesized. The synthesized zirconium doped manganese oxide OMS-2 materials have been characterized by XRD, TGA, BET and TEM techniques. All the materials showed the OMS-2 type (cryptomelane) X-ray diffraction patterns and the thermal stability and BET surface area of zirconium doped OMS-2 materials are improved compared to the parent manganese oxide (K-OMS-2) material. Transmission electron micrographs showed the rod like needle shaped morphology and zirconia dispersion on fibrous morphology of as-synthesized zirconium doped manganese oxide OMS-2 materials. As synthesized zirconium incorporated OMS-2 catalysts have been tested for the liquid phase oxidation of side chain aromatic compounds (ethylbenzene and benzyl alcohol) and cyclohexanol. Zr-K-OMS-2 (Cry) has shown high conversion for ethylbenzene and benzyl alcohol, whereas Zr-K-OMS-2 (Bir) has shown high activity for the conversion of cyclohexanol and good selectivity towards the formation of cyclohexanone.