Highly Loaded and Dispersed Ni2P/Al2O3 Catalyst with High Selectivity for Hydrogenation of Acetophenone

Highly loaded and dispersed Ni2P/Al2O3 catalyst was prepared by the phosphidation of Ni/Al2O3 catalyst with Ni loading of 80 wt.% in liquid phase and compared with the Ni/Al2O3 catalyst for the hydrogenation of acetophenone. X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) etc. were used to characterize the textural and structural properties of the prepared catalysts. It was found that the Ni/Al2O3 and Ni2P/Al2O3 catalyst possessed high surface area, loading and dispersion. The Ni/Al2O3 catalyst had higher apparent activity while the Ni2P/Al2O3 catalyst had higher intrinsic activity for the hydrogenation of acetophenone (AP). Remarkably, the Ni2P/Al2O3 catalyst exhibited high selectivity to 1-phenylethanol, due to repulsion of the phosphorous (Pδ−) for phenyl group and attraction of the nickel (Niδ+) for oxygen atom of carbonyl group, leading to preferential hydrogenation of carbonyl group in acetophenone. The effect of the particle size of the catalyst on the chemical selectivity might be another reason for high selectivity on the Ni2P/Al2O3 catalyst.