Highly active and stable CeO2-SiO2 supported Cu catalysts for the hydrogenation of methyl acetate to ethanol

A series of Cu-CeO2-SiO2 catalysts for the hydrogenation of methyl acetate to ethanol with different CeO2 contents was prepared by an ammonia-evaporation method. Compared with the Cu-SiO2 catalyst, the catalytic activity and stability of the Cu-CeO2-SiO2 catalyst were greatly enhanced with an optimized CeO2 content of about 30 wt.%. The structures of the catalysts were characterized by N-2 physisorption, N2O chemisorption, X-ray diffraction, H-2 temperature-programmed reduction, NH3-temperature programmed desorption and X-ray photoelectron spectroscopy. The results showed that adding an appropriate amount of cerium to Cu-SiO2 catalysts strengthened the interaction between the cupreous species and the support, diminished the copper crystallite size, improved the copper dispersion and enriched the surface Cu+ species. In addition, several characterizations were performed to investigate the structure changes of the catalysts after stability test, which demonstrated that the CeO2-modified Cu-SiO2 catalyst restrained the aggregation and valence change of cupreous species under reaction conditions. (C) 2015 Elsevier B.V. All rights reserved.