Xavier, K O; Chacko, J; Mohammed Yusuff, K K(Elsevier, Applied Catalysis A :General, September 4, 2003)
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Abstract:
Co(II), Ni(II) and Cu(II) complexes of dimethylglyoxime and N,N-ethylenebis(7-methylsalicylideneamine) have been synthesized in situ
in Y zeolite by the reaction of ion-exchanged metal ions with the flexible ligand molecules that had diffused into the cavities. The hybrid
materials obtained have been characterized by elemental analysis, SEM, XRD, surface area, pore volume, magnetic moment, FTIR, UV-Vis
and EPR techniques. Analysis of data indicates the formation of complexes in the pores without affecting the zeolite framework structure, the
absence of any extraneous species and the geometry of encapsulated complexes. The catalytic activities for hydrogen peroxide decomposition
and oxidation of benzyl alcohol and ethylbenzene of zeolite complexes are reported. Zeolite Cu(II) complexes were found to be more active
than the corresponding Co(II) and Ni(II) complexes for oxidation reactions. The catalytic properties of the complexes are influenced by their
geometry and by the steric environment of the active sites. Zeolite complexes are stable enough to be reused and are suitable to be utilized as
partial oxidation catalysts.