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Abstract
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Trinuclear metal clusters of Co, Mn and mixtures of Co/Mn including [Mn3(O)(CH3COO)6-(py)3]-Y,
[Co3(O)(CH3COO)6-(py)3], [Co2Mn(O)(CH3COO)6-(py)3]-Y and [CoMn2(O)(CH3COO)6-(py)3]-Y] were
prepared inside the nanocage of dealuminated Y zeolite by the template synthesis method. These
catalysts were characterized by Fourier transform infrared, Ultraviolet-visible, field scanning electron
microscopy, X-ray diffraction and atomic absorption spectroscopy. The encapsulated metal
clusters showed good catalytic activity in the epoxidation of cyclohexene with H2O2/O2. Epoxide
yields were 82.5% to 90.7%. NaBr was used as a promoter for the oxidation. The homonuclear
metal clusters showed higher catalytic activity than the others and the highest efficiency was with
the Mn3(O)-DAZY compound. The catalytic activity order was Mn3(O)-DAZY Co3(O)-DAZY
Mn2Co(O)-DAZY MnCo2(O)-DAZY.
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