Host (dealuminated Y zeolite)-guest (trinuclear metal clusters of Co, Mn and Cox/Mny) as nanocomposite catalysts for the epoxidation of cyclohexene

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.

Graphical AbstractThe synthesis, characterization and investigation of the catalytic activity of [Mn3(O)(CH3COO)6-(py)3]-Y (M=Co, Mn, Co/Mn) for the epoxidation of cyclohexene with H2O2/O2 in CH3COOH as solvent and with NaBr as a promotor was reported.Figure optionsDownload full-size imageDownload as PowerPoint slide