Preparation of Copper Modified Nickel-based Catalysts and Their Catalytic Hydrogenation Performance of Biphenyl

A series of copper modified nickel-based catalysts (xNi-yCu/Al2O3, x, y is the content of Ni and Cu, respectively, on the base of the mass of Al2O3, the same below) were prepared by impregnation method for the hydrogenation of biphenyl to cyclohexylbenzene (CHB). The prepared catalysts were characterized by X-ray powder diffraction (XRD), BET measurement, scanning electron microscope (SEM) and transmission electron microscope (TEM). The effects of catalyst (50%Ni-10%Cu/Al2O3) dosage, H2 pressure and reaction temperature on the hydrogenation of biphenyl to cyclohexylbenzene. The results showed that Cu particles on the surface of catalyst preferentially separated out, which could dilute Ni activity centers and lead to smaller Ni active particles, thus enhancing the selectivity of CHB. The conversion of biphenyl and the selectivity for CHB could reach 94.7% and 99.8%, respectively, under the conditions of 50%Ni-10%Cu/Al2O3 0.5 g, cyclohexane as a solvent, H2 pressure 2.2 MPa, reaction temperature 200℃ and reaction time 4 h. In addition, the conversion of biphenyl decreased slightly, while the selectivity for CHB was almost unchanged after 50%Ni-10%Cu/Al2O3 being recycled for nine times. © 2018, Editorial Office of FINE CHEMICALS. All right reserved.