Preparation, Characterization And Hydrogenation Activity Evaluation Of Unsupported Bimetallic Catalyst

In this paper, a series of unsupported bimetallic catalysts were prepared with the porous bimetallic mixed oxides synthesized by high-temperature hydrothermal method. The main research contents are as follows.A series of Ni-Mo, Ni-W, Co-Mo and Co-W mixed oxides were synthesized by high-temperature hydrothermal method, and characterized by TG-DTA, XRD, BET, SEM and HRTEM. The effects of synthesizing process and synthetic additive on the structure of Ni-Mo mixed oxides were also investigated. The unsupported catalysts were prepared with their mixed oxides by a certain forming technology and BET, Py-IR were employed to characterize the as-prepared catalysts. The unsupported Ni-Mo, Ni-W, Co-Mo and Co-W sulfides catalysts were characterized by XRD and HRTEM, and the hydrogenation performance of the different unsupported bimetallic catalysts were studied in a fixed-bed high pressure micro-reactor with dibenzothiophene (DBT) as model compound.The activities of the unsupported bimetallic catalysts were evaluated utilizing FCC diesel oil as the material. It was found that higher activity of HDS and HDN was obtained with the binder of SB than that with aluminium hydrate. Hydroproceesing activity was enhanced when adding polyglycol into the Ni-Mo mixed oxides. The ratio of HDS and HDN could reach 99.2 % and 99.7 % respectively, and the enhancement of the cetane number was about 18.8 units. Comparing the hydroproceesing activity of unsupported catalysts with industrial supported catalyst RN-10B, it was shown that the order of the catalytic performance was Ni-Mo > Ni-W > Co-Mo > Co-W > RN-10B. And the relative desulfurization activity of unsupported Ni-Mo catalysts is 6.9 times higher than that of RN-10B catalyst. It means that the hydroproceesing activity of unsupported catalyst is obviously higher than that of supported catalysts.