A novel Co-Mo-Ni/gamma-Al2O3 catalyst with a hierarchically macro-/mesoporous structure was prepared for the hydrodesulfurization of thiophene. The catalyst support and catalyst were characterized by N-2 adsorption-desorption, scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), and energy-dispersive spectrometry (EDS) techniques. The hierarchically porous structure of the novel catalyst, i.e., the parallel arrays of macroporous channels and the accessible mesopores present in the walls that separated the macrochannels, was well preserved after high-pressure pelletization. Compared with a commercial Co-Mo-Ni/gamma-Al2O3 catalyst, which had similar physicochemical properties with the novel catalyst except for the absence of macropores, the novel catalyst exhibited much higher hydrodesulfurization activity in the apparent kinetic region though similar activities were observed for the two catalysts in the intrinsic kinetic region. This result revealed the significant effect of the hierarchically macro-/mesoporous structure. Based on the experimental data, intrinsic and apparent activation energies of thiophene hydrodesulfurization for the novel catalyst were 65.8 and 50.8 kJ/mol, respectively, while the corresponding values for the commercial catalyst were 69.9 and 35.0 kJ/mol, respectively. The much lower apparent activation energy for the commercial catalyst further evidenced the diffusion-enhanced effect of the hierarchically porous structure of the novel Co-Mo-Ni/gamma-Al2O3 catalyst. (C) 2011 Elsevier B.V. All rights reserved.