Ni-promoted MoS2 in hollow zeolite nanoreactors: enhanced catalytic activity and stability for deep hydrodesulfurization

Abstract

Improving the intrinsic catalytic activity of the active phases and mass transfer of the reactants and products are key issues in heterogeneous catalysis. Herein, we construct hollow zeolites with a thin shell of about 10 nm and mesopore structure as supports to load NiMoS_X catalysts. On one hand, the nanocages with hollow structures can effectively confine the growth of NiMoS_X catalysts, leading to a shorter slab length, higher sulfidation degree, more Ni–Mo–S active sites, and enhanced intrinsic activity. The deep hydrodesulfurization (HDS) activity for dibenzothiophene (DBT) of the NiMoS_X/Hol-ZSM-5 catalyst is superior to that of NiMoS_X on nanosized ZSM-5 with a reaction rate constant k_HDS value of 18.74 × 10⁻⁷ mol g⁻¹ s⁻¹. On the other hand, the accessible nanocages and mesopore structure greatly facilitate the mass transfer process and inhibit the formation of carbon deposits, which enhances the HDS stability of NiMoS_X/Hol-ZSM-5 to over 80 h. This hollow structure-confined strategy sheds light on the design of novel highly efficient supported catalysts, which we believe could be extended to other heterogeneous catalysis systems.