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Three-dimensional flower-like α-Fe 2 O 3 nanostructures have been successfully synthesized by a simple surfactant-free environmental friendly solvolthermal process. The as-prepared products were investigated by X-ray powder diffraction, transmission electron microscopy, and field emission scanning electron microscopy. By adjusting the synthetic parameters, the shape of the α-Fe 2 O 3 nanostructures can be controlled. The three-dimensional flower-like α-Fe 2 O 3 nanostructures were found to be highly active as catalysts for phenol alkylation. The effects of various parameters, such as reaction temperature, reaction time and the amount of catalyst, were studied. The catalyst was stable and could be reused three times in normal atmosphere without suffering appreciable loss in catalytic activity.

A novel environmentally benign Heck reaction using Ni nanoparticles as catalysts under hydrothermal conditions has been developed in the absence of phosphine ligands without the protection of an inert atmosphere. The results showed that the aryl iodides and bromides could carry out the coupling reaction with a variety of alkenes by hydrothermal treatment. More importantly, the cheap catalysts are stable under the reaction conditions and retain good to moderate activity for at least six successive runs without any additional activation treatment. This approach would be very useful from a practical viewpoint.

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