Cu₉-Al_x-Mg_y catalysts for hydrogenation of ethyl acetate to ethanol

Cu₉-Al_x or Cu₉-Al_x-M_y (M = Mg, Ca, Ba or Sr) catalysts were prepared by a deposition-precipitation method, characterized by means of H₂-TPR, XRD and N₂ sorption, and applied for hydrogenation of ethyl acetate to ethanol in a fixed-bed reactor. The molar ratio of Cu/Al or Cu/Al/M and the reaction parameters were investigated thoroughly. As a result, the Cu₉-Al_0.5-Mg_1.5 catalyst with higher specific surface area, lower initial reduction temperature and better metal dispersion furnished 97.8% ethyl acetate conversion with 98% selectivity to ethanol under optimal reaction conditions. Moreover, the Cu₉-Al_0.5-Mg_1.5 catalyst also showed good lifetime and neither the activity nor selectivity decreased during 210 h test. Based on the characterization of the Cu₉-Al_0.5-Mg_1.5 catalyst, the optimal Cu⁺/Cu⁰ proportion played a key role in determining the superior performance.