Few-Layered Defect-Rich MoS2 Nanosheets with Ni Doping as Catalysts for Efficient Hydrodesulfurization Reaction

Unsupported MoS2 nanosheets are promising hydrodesulfurization (HDS) catalysts that can effectively convert sulfur species in diesel to hydrocarbons and H2S during the production process of fossil fuels. However, the active site density of MoS2-based catalysts is limited due to the existence of a large amount of inert basal planes, hindering the improvement of MoS2 HDS activity. Herein, a strategy that combines defect control and metal doping is proposed to boost the catalytic activity of unsupported MoS2 nanosheets. By adjusting hydrothermal reaction conditions, few-layered defect-rich MoS2 (DR-MoS2(FL)) is synthesized to significantly enhance the HDS efficiency, which is further improved by incorporating Ni atoms in basal planes, achieving the highest thiophene conversion of 92.3% at 280 C-degrees. Moreover, the Ni-doped DR-MoS2(FL) catalyst exhibits excellent stability with the high activity retained in the recycling reaction. The effect of Ni dopants on the electronic structure and adsorption behavior of the MoS2 basal planes is demonstrated by density functional theory calculation. This work reveals a facile method to tailor the basal planes with the formation of more Ni-Mo-S active sites for highly efficient MoS2 HDS catalysts.