Green synthesis of nano-CuFe2O4/clinoptilolite and its use in benzodiazepine synthesis

Abstract

In this research, a copper ferrite (CuFe2O4) nanocatalyst stabilized on clinoptilolite (CP) was prepared using green tea (Camellia sinensis) leaf extract. Fourier transform infrared spectra, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray analysis, transmission electron microscopy (TEM), the Brunauer–Emmett–Teller (BET) method, thermogravimetric analysis and differential thermal analysis were used to characterize copper ferrite/CP. After fixation on CP, the crystallite size of copper ferrite was determined to be 48.7 nm using an XRD pattern and the Debye–Scherrer equation. Copper ferrite nanoparticles were successfully placed on CP as evidenced by FESEM and TEM images. Using the Barrett–Joyner–Halenda method, the average diameter of the catalyst pores was found to be 22.2 nm. Using the BET method, the catalyst surface area was estimated to be 43.7 m2/g. The catalytic activity of copper ferrite/CP in the production of benzodiazepine (the reaction of o-phenylenediamine with ketones) was examined. The experimental results showed that this catalyst performs well under mild reaction conditions. Using an external magnetic field, copper ferrite/CP was easily separated from the reaction product and can be reused without appreciably decreasing its catalytic activity.