Egg-shell type catalysts, in which a thin layer of catalytically active component is distributed on the outer surface of the support particle, have been theoretically and experimentally proved to be useful in processes where the reaction has a very high rate and the intraparticle diffusion becomes the limiting step. Herein we report the preparation of an egg-shell Al2O3-supported nickel (Ni/Al2O3) catalyst derived from layered double hydroxides (LDHs) precursor, and its catalytic performance for selective hydrogenation of pyrolysis gasoline (PyGas), an important by-product of ethylene industry from thermal decomposition of heavier oil fractions, which was carried out in the liquid phase. Firstly, a Ni2+Al3+-containing LDHs (NiAl-LDHs) precursor was in situ grown on the surface of gamma-Al2O3 spheres by using a diluted ammonia solution as precipitator. Then, egg-shell Al2O3-supported nickel oxide (NiO/Al2O3) sample with NiO crystallites highly dispersed on the external edge of the Al2O3 support was obtained after calcination at 450 degrees C. The experimental study of selective hydrogenation of styrene (PyGas model 1) for revealing the intrinsic hydrogenation kinetics was carried out in a batch reactor at 60 degrees C using the egg-shell Ni/Al2O3 catalyst (denoted LP-Ni/Al2O3; LP is expressed as layered precursor) fabricated by subsequent ex situ presufidation and final H-2 reduction at 500 degrees C of the NiO/Al2O3 sample. In addition, an Ni/Al2O3 catalyst with uniform distribution of Ni in the catalyst was prepared by a conventional wet impregnation method (denoted IM-Ni/Al2O3; IM is expressed as impregnation method) with the consistent Ni loading amounts and given into the consideration for comparison. The estimated effectiveness factor (eta) of the LP-Ni/Al2O3 catalyst was higher than that of the IM-Ni/Al2O3 one, demonstrating the catalyst with eggshell structure has a lower intraparticule mass transfer resistance. The catalytic hydrogenation activities of both Ni-based catalysts were further evaluated by selective hydrogenation of diolefins (PyGas model 2), along with selective hydrogenation of PyGas model 1, in a micro-flow reactor. The egg-shell Ni/Al2O3 catalyst derived from LDHs precursor exhibited a superior catalytic hydrogenation performance, which mainly be due to Ni metal being deposited on the Al2O3 support in a much thinner outer layer, as well as a smaller average size of nickel particles with stronger interaction between the nickel species and support. Several characterization techniques including powder X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), low temperature N-2 adsorption-desorption, X-ray photoelectron spectroscopy (XPS), and temperature programmed reduction of hydrogen (TPR)/temperature programmed desorption of hydrogen (H-2-TPD) were adopted to investigate the physical-chemical properties of the two supported Ni catalysts in detail. (C) 2013 Elsevier B.V. All rights reserved.