Ni–Cu/Al2O3 catalysts for the selective hydrogenation of acetylene: a study on catalytic performance and reaction mechanism

Abstract

Aiming at the preparation of metal catalysts with nanoscale structures, Ni–Cu/Al₂O₃ nanoparticle catalysts (i.e., Ni&Cu-NP/γ-Al₂O₃), containing a certain amount of Ni and Cu were prepared for the hydrogenation of acetylene. The highly dispersed and stable Ni&Cu-NP/γ-Al₂O₃ catalyst with a Ni : Cu atomic ratio of 1 : 1 was obtained from a NiCl₂/CuCl₂ precursor by a modified co-precipitation method, the average size of which was controlled at 10.0 ± 0.3 nm. Under optimal reaction conditions, approximately 100% conversion and 71% selectivity at 130 °C were achieved using the Ni&Cu-NP/γ-Al₂O₃ catalyst. The enhanced selectivity was attributed to the formation of nickel–copper alloys, which have been identified by both diffuse reflectance infrared Fourier transform spectroscopy and theoretical calculation results.