Template-free synthesis of Cu@Cu2O core-shell microspheres and their application as copper-based catalysts for dimethyldichlorosilane synthesis

We report the synthesis of Cu@Cu2O core-shell microspheres via a facile template-free solvothermal method. The resulting products were characterized by X-ray diffraction, scanning electron microscopy with energy-dispersive spectroscopy, transmission electron microscopy, temperature-programmed reduction, and thermogravimetric analysis. It is found that, Cu2O microspheres were firstly formed through the reduction of copper acetate by glutamic acid, and then, the reduction started inside the microspheres due to the higher surface energies of inner Cu2O particles, resulting in the formation of Cu@Cu2O core-shell structure. The content of Cu core in the composite microspheres increased with the reaction time and temperature. The as-prepared Cu@Cu2O core-shell microspheres exhibited a better catalytic performance for dimethyldichlorosilane synthesis than pure Cu2O and Cu, and even superior to the physically mixed Cu and Cu2O microspheres possibly because of the synergistic catalytic effect. These Cu@Cu2O core-shell microspheres will have potential application in organosilicon industry as copper-based catalysts. (C) 2012 Elsevier B.V. All rights reserved.