Hydrodesulfurization (HDS) is one of the most efficient processes for removing sulfur-containing molecules such as dibenzothiophene (DBT) from oil, whatever fossil based or bio-based. However, hydrodesulfurization using molybdenum sulfides (MoS2) as catalytic active centers and transition metals (X) as promoters is seriously challenged by the insufficient catalytic activity and selectivity because of the separate phases of sulfides, and sparse X-Mo-S active sites, leading to poor synergistic effect between the X promoter and MoS2 active centers. Herein, atomically doped MoS2 catalysts (denoted as XMo, X = Fe, Co or Ni) were synthesized by using polyoxometalate template-based synthetic strategy were proposed. The pre-organized Anderson-type POMs, [XMo6O24H6]n− (X = Fe, Co or Ni), acted as a pre-assembled molecular platform with intimate X-Mo interactions, ensure the uniform formation of X-Mo-S active sites after sulfuration. The promoter atoms, including Fe, Co and Ni, enhanced the efficiency of hydrodesulfurization of MoS2. Particularly, NiMo exhibits the highest HDS activity, while CoMo shows a moderate HDS activity with the highest DDS selectivity (∼85 %). Despite the lowest HDS activities, FeMo with the cheapest Fe promoter, shows good DDS selectivity (∼70 %). Further study reveal NiMo has the most laminated morphology and highest stacking slabs, resulting in the highest HDS activity. Benefiting from the Co(Fe)-Mo-S structure and abundant sulfur vacancy, CoMo and FeMo showed great enhancement in the DDS selectivity. Moreover, the DDS selectivity of these designed catalysts were supported energetically by first principle calculations. This research will expand on the ability to improve the HDS activities and DDS selectivity by precisely engineering catalytic active sites to achieve significant synergistic effect in atomic scale.
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