Performance of SiO2–TiO2 Binary Oxides Supported Cu–ZnO Catalyst in Ethyl Acetate Hydrogenation to Ethanol

Abstract

SiO2, TiO2, and SiO2–TiO2 binary oxides supported Cu–ZnO catalysts prepared by co-precipitation method were compared in the hydrogenation of ethyl acetate (EA) to ethanol (EtOH), and it shows the SiO2–TiO2 binary oxides supported Cu–ZnO catalyst has a larger catalytic activity over the unitary SiO2 or TiO2 supported ones. Comprehensive characterizations by N2 adsorption, X-ray diffraction, H2-temperature programmed reduction, transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray induced Auger electron spectroscopy reveal that Cu–ZnO/SiO2–TiO2 catalyst has an appropriate Cu0/Cu+ molar ratio of about 1 with highly dispersed copper species and strong metal-support interaction. Furthermore, the electron transfer from TiO2 to copper species can accelerate the activation of C=O and improve the catalytic performance. Under the optimized reaction conditions of P = 2.0 MPa, T = 523 K, WHSV = 0.5 h−1, and n(H2)/n(EA) = 20, the conversion of EA was up to 96% with EtOH selectivity of 99.5%.