The design of base metal catalysts for hydrotreating reactions : temperature programmed sulphidation of NiW/Al2O3 catalysts and their activity in the hydrodesulfphurisation of thiophene and dibenzothiophene

NiW based hydrotreating catalysts have a good performance in hydrodesulphurisation reactions. It appeared that the their performance in the hydrodesulphurisation of dibenzothiophene and thiophene strongly depends on their sulphiding degree, which can be controlled by both the calcining and sulphiding temperature. By combining temperature programmed sulphiding with quasi in-situ XPS and activity measurements, it was concluded that the active phase for the HDS of DBT consist of either micro-crystalline sulphided Ni on a WO3 substrate, or of Ni2+ dissolved in the in NiWO4. In contrast, the active phase for the HDS of thiophene seems to consist of Ni-promoted WS2 structures