Recyclable Mesoporous Ceria Supported Gold Nanoparticles Based Catalyst for O-Arylation of Phenols.

Ceria supported gold nanoparticles (Au-CeO2 NPs) were prepared by a simple deposition-precipitation method. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and Raman analysis indicated the formation of gold nanoparticles over phase pure cerianite ceria support. The presence of gold nanoparticles was well identified by UV-DRS study. In addition, the field emission scanning electron microscope (FESEM) and high resolution transmission electron microscope (HR-TEM) images revealed that the maximum number of particles having spherical shape were approximately 10 nm size. Subsequently, surface area of the catalyst determined from BET, Langmuir and DFT methods were found to be 83.1, 134 and 85.2 m2 g(-1) respectively. N2 absorption-desorption measurement revealed that Au-CeO2 NPs was mesoporous in nature. Au-CeO2 NPs proved to be an efficient catalyst for the O-arylation reactions. The reaction conditions were optimized using 2,6-dimethoxyphenol and 1-chloro-4-nitrobenzene as a model substrate by changing the solvent, base, quantity of catalyst, and temperature. The scope of the work was extended to various substituted phenols and aryl halides (F, Cl and Br) and reusability of catalyst was tested for four cycles which showed no loss in its activity.