Transformation of ethanol to ethyl acetate over Cu/SiO2 catalysts modified by ZrO2

Direct transformation of ethanol to ethyl acetate was investigated on a series of Cu(ZrO2)/SiO2 catalysts. Inductively coupled plasma(ICP), surface area analysis, X-ray diffraction(XRD), H-2-temperature programmed reduction(H-2-TPR), X-ray photoelectron spectroscopy(XPS), NH3-temperature programmed desorption(NH3-TPD) and Fourier transform-infrared spectroscopy(FTIR) techniques were used to characterize the catalysts. The results reveal that ZrO2 can improve the dispersion of copper species and increase the acidity of the Cu(ZrO2)/SiO2 catalysts. The Cu-0 is responsible for ethanol dehydrogenation to acetaldehyde, and both the Lewis acid and Bronsted acid sites were in favor of the selectivity to ethyl acetate. The synergistic effect of Cu-0 and an appropriate amount of acidic sites played an important role in the production of ethyl acetate.