A novel efficient magnetic core–zeolitic shell nanocatalyst system: preparation, characterization and activity

Abstract

Analcime shell-nickel ferrite core microspheres were decorated with Pd and Pt nanoparticles with the aid of an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6). The samples thus prepared were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), nitrogen adsorption-desorption isotherms, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) methods. The XRD patterns confirmed the growth of a zeolitic layer on the surface of the magnetic cores. The thermogravimetric analysis (TGA) curve clearly indicated the thermal decomposition of the loaded IL, which confirmed the presence of BMIM-PF6 in the structures. In addition, EDX analysis indicated that the samples contained 2.5 mass % of noble metal. The metallic species can be adsorbed on the modified surface and/or penetrate into the zeolitic channels in the structures. The results indicate that the X-IL/An/S/NF (X = Pt or Pd) metallic nanoparticles supported core-shell catalystssamples were able to catalyse the selective oxidation of cyclohexene to 2-cyclohexene-1-ol under the induced conditions. The catalysts continued to be active after recycling up to 5 times. Eventually, a suitable mechanism was proposed for the selective oxidation of cyclohexene over the catalysts.