Preparation of two-dimensional TiO2-Al2O3 support and its application in hydrodenitrification

MIN Bingzhu; ZHANG Meng; WANG Xingbao; LI Wenying

doi:10.13226/j.issn.1006-6772.23110802

Abstract：Processing and utilization of high-yield coal tar in China can alleviate the energy shortage.Hydrodenitrogenation(HDN)of coal tar is a significant way to utilize coal tar in a clean and efficient manner,and the key is the preparation of high performance HDN catalyst.There is a strong interaction between traditional Al2O3 and supported active metals,which affects the hydrogenation performance.Based on the special surface properties and layered structure of the two-dimensional support,a novel support material was prepared by modifying Al2O3 with graphene oxide as structure director and TiO2 as the modifier.A set of NiMoS/TiO2-Al2O3 catalysts were prepared by impregnation process and used in the quinoline HDN reaction.The effects of carrier dimensions on the structure of support and the catalytic performance of NiMoS catalysts for HDN were investigated.When HDN reaction was performed at 350 ℃ and 3 MPa(H2)for 4h,compared with those of three-dimensional supported catalysts,the conversion rate of quinoline increased from 94.2％to 99.4％.The nitrogen removal efficiency of quinoline increased from 0.6％to 74.8％,the yields of propylcyclohexane and propylbenzene 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 further hydrogenation 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,high dispersion of MoS2 on the carrier surface,small cluster parti cles,weak metal-support interaction.And it is easily sulfurized to generate more active NiMoS phases,so it displays better catalytic HDN performance compared with the NiMoS catalyst supported by three-dimensional TiO2-Al2O3.