Characteration And Microstructure Of NiMoS Active Phase With Bimetallic Complex As Precursor

Research has been carried out on the information of nickel(Ni), molybdenum(Mo) and in bimetallic NiMo-solutions using citric acid as a chelating agent,which are used for the preparation of Al2O3-supported hydrodesulphurization(HDS) catalysts.Using dibenzothiophene(DBT) as the model compound of HDS, the test of HDS performance and the characterization of the Ni-Mo-S phase were also reported. The impregnation solution of bimetallic Ni-Mo-CA compound was prepared by ammonium heptamolybdate, citric acid(CA) and nickel nitrate. The influence of different molar ratio of Mo atom to citric acid, the different impregnation order of Ni and Mo metallic components, different ratio of Ni to Mo atom and different condition of thermal treatment on the catalytic activity of NiMoCA/γ-Al2O3 has been studied.It is found that NiMo catalyst with bimetallic complex as precursor shows similar desulfurization activity and comparable hydrogenation selectivity with its reference catalyst.The structure of the MoS2 activity phase of NiMoCA/γ-Al2O3 is studied by TEM. It shows that the use of bimetallic complex as the precursor has a significant controlling effect on the microstructure size of MoS2 activity phase, which can make the the distribution of stacking numbers focus on 3 and control the slab length in the range of 2~4nm.