Hydrogenation Performance of Acetophenone to 1-Phenylethanol on Highly Active Nano Cu/SiO2 Catalyst

Abstract

In this work, highly active nano Cu/SiO2 catalysts with various copper content were prepared by urea homogeneous precipitation method. The catalysts were characterized by N2 adsorption, XRD, H2-TPR, XPS and TEM. It was found that the nano Cu/SiO2 catalyst displayed excellent catalytic performance for the selective hydrogenation of acetophenone (AP) to 1-phenylethanol (PhE) when copper content was 25 wt%. The Cu/SiO2 catalyst had well dispersed copper species, small particle size, high BET surface area (ca. 540 m2/g) and abundant pore structure. The influence of different reaction conditions on the hydrogenation process were also discussed. AP conversion and the PhE selectivity reached 99.8% and 99.08%, respectively, under the optimal reaction conditions (Temperature: 353 K; Pressure: 2.0 MPa, LHSV: 1.0 h−1 and the molar ratio of H2/AP:15). Besides, the above catalyst maintained a high catalytic performance in the duration of 500 h operation. The synergistic effect between Cu+ and Cu0 improved the activity and stability of Cu/SiO2 catalyst. The research indicated that the catalyst had a wide industrial prospect. The Cu/SiO2 catalyst showed a good performance for AP hydrogenation. The reduced Cu/SiO2 catalyst contains both Cu+ and Cu0 consistent with XPS. Cu+ sties stabilize the methoxy and acyl species and Cu0 facilitates the decomposition of H2. Phenyl in AP and Cu had electrostatic repulsion, which was favorable for desorption of PhE.