Synthesis and characterization of functionalized NaP Zeolite@CoFe2O4 hybrid materials: a micro–meso-structure catalyst for aldol condensation

Abstract

In this work, magnetic nanocomposite of NaP Zeolite and CoFe2O4 as magnetic nanoparticles (MNP’s) with different ratios were prepared and in the second step functionalized with 2-aminopyridine as a basic group. All samples were characterized by FT-IR, XRD, VSM, FESEM, EDX, TEM, and BET and thermal analyses. The results show that CoFe2O4 MNP’s was dispersed on NaP Zeolite without any significant aggregation with particle size about 30–50 nm. The BET and TEM confirmed the presence of mesoporous phase in the surface of NaP Zeolite/CoFe2O4 and preparation a micro–meso-structure. The NaP Zeolite/CoFe2O4 and NaP Zeolite/CoFe2O4/Am-Py were used as acid–base catalysts for aldol condensation of cyclohexanone with benzaldehyde, and furfural with acetone which produce curcumin and biofuel intermediates, respectively, in solvent-free condition. The effect of different factors such as the percent of CoFe2O4 MNP’s, catalyst amount, solvent, time and temperature was investigated. The catalyst was easily separated with an external magnet and reused four times without significant change in the yield. These catalysts have various advantages including high loading capacity, low leaching for CoFe2O4 MNP’s and simple and efficient recovery procedure which can be used under mild and ecofriendly condition.