Hierarchically macro-/mesoporous structured Al

2

O

3

and TiO

2

-Al

2

O

3

materials were used as supports to prepare novel Co-Mo-Ni hydrodesulfurization (HDS) catalysts. A commercial Co-Mo-Ni/Al

2

O

3

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)

N

2

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/TiO

2

-Al

2

O

3

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.