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 theoxidation. The homonuclear metal clusters showed higher catalytic activity than the othersand 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
