Hierarchically macro-/mesoporous structured Al2O3 and TiO2-Al2O3 materials were used as supports to
prepare novel Co-Mo-Ni hydrodesulfurization (HDS) catalysts. A commercial Co-Mo-Ni/Al2O3 catalyst without
macroporous channels was taken as a reference. The catalysts were characterized by scanning electron microscope
(SEM), transmission electron microscope (TEM), energy-dispersive spectrometry (EDS), N2 adsorption-desorption,
X-ray diffraction (XRD), and temperature programmed reduction (TPR). The apparent activities of the hierarchically
porous catalysts for thiophene HDS were superior to those of the commercial catalyst, which was mainly ascribed
to the diffusion-enhanced effect of the hierarchically bimodal pore structure. The addition of titania to alumina
in the support helped to weaken the interaction between the active phase and the support, and as a result, the
novel Co-Mo-Ni/TiO2-Al2O3 catalyst with a low titania loading (28%, by mass) in the support exhibited high HDS
activities, even without presulfiding treatment. However, the catalyst with a high titania loading (61%, by mass)
showed much lower activities, which was mostly caused by its low surface area and pore volume as well as the
non-uniform distribution of titania and alumina. The kinetic analysis further demonstrated the support effects on
HDS activities of the catalysts.