Boosting ultra-deep hydrodesulfurization of diesel by tuning sulfidation degree of metals on NiMo/AlOOH catalyst.

• A room-temperature process was developed to prepare catalyst for hydrodesulfurization reaction. • S content of diesel was reduced from 18000 μg g−1 to 3 μg g−1. • The catalyst showed an excellent long-term stability. • Excellent performance of the catalyst was originated from the appropriate sulfidation degree of Mo. By using a room-temperature discharge-based sulphurization (RT-DS) process, we efficiently tune sulfidation degree of metal on γ -AlOOH-supported NiMo catalyst via simply changing feedstock amount for preparing catalysts, thus preparing a NiMoS/AOH-4 catalyst for hydrodesulfurization (HDS) of diesel. NiMoS/AOH-4 shows an excellent HDS performance, with S content of diesel being reduced from 18000 μg g−1 to 3 μg g−1 and without catalytic efficiency decrease after 1000 h reaction. Moreover, NiMoS/AOH-4 shows higher rate constant, higher turnover frequency but lower activation energy in HDS reaction, as compared with those on widely reported catalysts. The excellent HDS performance of NiMoS/AOH-4 is resulted from the appropriate sulfidation degree of Mo, which creates more abundant catalytic active Ni-Mo-S phases. RT-DS process for preparing NiMoS/AOH-4 proceeds in Ar at room temperature and atmospheric pressure, without using H 2 S and heating. This makes RT-DS process suitable for large-scale industrial applications to fabricate more efficient HDS catalysts. [ABSTRACT FROM AUTHOR]