Magnetic Crosslinked Copoly(ionic liquid) Nanohydrogel Supported Palladium Nanoparticles as Efficient Catalysts for the Selective Aerobic Oxidation of Alcohols

Nowadays it is still a great sustainable processes challenge to produce efficient, selective and easy magnetic recovery and recycling catalysts for oxidation of alcohols using air as the oxidant [1,2]. In this work a new magnetic nanohydrogel comprising [DABCO-allyl][Br] ionic liquid, allyl alcohol and N,N -methylene-bis (acrylamide) has been used for stabilization of small and highly uniform palladium nanoparticles of 3-4 nm size (MXCPILNHG@Pd). It was characterized by Fourier-transform infrared spectroscopy (FTIR), atomic adsorption spectroscopy (AAS), thermogravimetric analysis (TGA) transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), SEM-Map, energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectra (XPS), vibrating-sample magnetometer (VSM), and dynamic light scattering (DLS). According to optimization of cross-linking degree and ratio of DABCO-IL, MXCPILNHG-2@Pd found as a highly selective catalyst in oxidations of primary alcohols to the corresponding aldehydes in toluene and to acids in water. Furthermore, secondary alcohols were reacted efficiently to corresponding ketones in both toluene and water. Catalyst was magnetically recovered and recycled for several times in both toluene and water and reused catalysts were characterized by TEM and XPS.