Processing and utilization of high-yield coal tar in China can alleviate the energy shortage. Hydrodenitrogenation (HDN) ofcoal tar is a significant way to utilize coal tar in a clean and efficient manner,and the key is the preparation of high performance HDNcatalyst. There is a strong interaction between traditional Al2O3 and supported active metals,which affects the hydrogenationperformance. Based on the special surface properties and layered structure of the two-dimensional support,a novel support material wasprepared by modifying Al2O3 with graphene oxide as structure director and TiO2 as the modifier. A set of NiMoS/TiO2−Al2O3 catalystswere prepared by impregnation process and used in the quinoline HDN reaction. The effects of carrier dimensions on the structure ofsupport and the catalytic performance of NiMoS catalysts for HDN were investigated. When HDN reaction was performed at 350 ℃ and3MPa (H2) for 4h,compared with those of three-dimensional supported catalysts,the conversion rate of quinoline increased from94.2% to 99.4%. The nitrogen removal efficiency of quinoline increased from 0.6% to 74.8%,the yields of propylcyclohexane andpropylbenzene were 58.4% and 13.4%,respectively. The results indicate that the supported two-dimensional NiMoS/TiO2−Al2O3 catalyst possesses better HDN performance. The geometrical structure of support and modified catalyst was further analyzed. It is found that two-dimensional TiO2−Al2O3 carrier exists porous lamellar structure,high proportion of Lewis acid,which is conducive to furtherhydrogenation of 1,2,3,4-tetrahydroquinoline and open-loop of decahydroquinoline. Thereby the denitrogenation product,propylcyclohexane is generated. The NiMoS catalyst supported by two-dimensional TiO2−Al2O3 exists large specific surface area,highdispersion of MoS2 on the carrier surface,small cluster parti cles,weak metal-support interaction. And it is easily sulfurized to generatemore active NiMoS phases,so it displays better catalytic HDN performance compared with the NiMoS catalyst supported by three-dimensional TiO2−Al2O3.