In this work

NiMo catalysts with various contents of MoO

3

were prepared through incipient wetness impregnation by a two-step method (NM-

x

A) and one-pot method (NM-

x

B). The catalysts were then characterized by XRD

XPS

NH

3

-TPD

H

2

-TPR

HR-TEM

and N

2

adsorption-desorption technologies. The performance of the NiMo/Al

2

O

3

catalysts was investigated by hydrocracking low-temperature coal tar. When the MoO

3

content was 15 wt%

the interaction between Ni species and Al

2

O

3

on the NM-15B catalyst was stronger than that on the NM-15A catalyst

resulting in the poor performance of the former. When the MoO

3

content was 20 wt%

MoO

3

agglomerated on the surface of the NM-20A catalyst

leading to decreased number of active sites and specific surface area and reduced catalytic performance. The increase in the number of MoS

2

stack layers strengthened the interaction between Ni and Mo species of the NM-20B catalyst and consequently improved its catalytic performance. When the MoO

3

content reached 25 wt%

the active metals a

gglomerated on the surface of the NiMo catalysts

thereby directly decreasing the number of active sites. In conclusion

the two-step method is suitable for preparing catalysts with large pore diameter and low MoO

3

content loading

and the one-pot method is more appropriate for preparing catalysts with large specific surface area and high MoO

3

content. Moreover

the NM-

x

A catalysts had larger average pore diameter than the NM-

x

B catalysts and exhibited improved desulfurization performance.