Engineering the accessibility of active sites in mixed 1 T-2H MoS2 nanoflowers via NaClO etching for deep hydrodesulfurization of dibenzothiophene

[Display omitted] •The accessibility of active sites in MoS2 slabs were tuned by NaClO etching.•Sodium ion insertion with high concentrations increased the proportions of 1 T-MoS2.•1 T-MoS2 provided more coordinatively unsaturated sites than 2H-MoS2.•The sulfided MoS2-N-1.0 catalyst exhibited the optimal DBT HDS activity. A NaClO etching strategy was adopted to engineer the active structure of mixed 1T-2H MoS2 nanoflowers and prepare efficient hydrodesulfurization (HDS) catalysts. In the original MoS2-P catalyst, the 2H-MoS2 phase was exposed after MoS2 slabs were etched using NaClO. Sodium ion insertion with high concentrations increased the interlayer spacing of MoS2 slabs and increased the transformation of 2H-MoS2 to 1T-MoS2 phases. With increase in the concentration of NaClO solution, the proportions of 1T-MoS2 in the MoS2-N-x catalysts initially increased and then decreased. They then reached a maximum when the NaClO concentration was 1.0 mol/L. Owing to the thermodynamic instability of 1T-MoS2, the proportions of 1T-MoS2 in the sulfided MoS2-P and MoS2-N-x catalysts were less than those of the corresponding unsulfided catalysts. However, among sulfided MoS2-P and MoS2-N-x catalysts, the sulfided MoS2-N-1.0 catalyst demonstrated the highest proportion of the 1T-MoS2 phase, the best dispersion of the MoS2 slabs, and the most coordinatively unsaturated sites, thus providing itself with the optimal HDS performance for removing dibenzothiophene.