Ordered mesoporous MCM-41 containing cobalt ferrite as high-performance catalyst in the synthesis of 5-substituted 1H-tetrazoles and oxidation of sulfides

Abstract

A multifunctional catalyst with attractive recuperation was manufactured by impregnating 4-dimethylamino pyridine (MP) with Ni supported on MCM-41 coated with CoFe₂O₄ (MCM-41/CoFe₂O₄/MP/Ni), which effectively acted as a selective catalyst for the synthesis of tetrazole and selective oxidation of sulfide with high effectiveness. The structures of the hybrid were examined by high-resolution transmission electron microscopies (TEM), field emission scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDS), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), vibrating-sample magnetometer (VSM), elemental mapping, and nitrogen adsorption−desorption isotherm. The hexagonal system of MCM-41 is well preserved after CoFe₂O₄ and 4-dimethylamino pyridine/Ni embedding. Results showed that the magnetite nanoparticles were coated with the MCM-41 silica with the formation of core–shell structured materials, and the 4-dimethylamino pyridine (MP) was successfully immobilized on the core–shell structured support. In this approach, the MCM-41/CoFe₂O₄/MP/Ni composite with spherical particles consisted of a mesoporous structure. This catalyst was recovered and reused several times without significantly decreasing efficiency and stability.