The Influence of Metal–Support Interactions on the Performance of Ni-MoS2/Al2O3 Catalysts for Dibenzothiophene Hydrodesulfurization

Abstract

In this present work, a new kind of sulfurized hydrodesulfurization catalyst was synthesized via the hydrothermal treatment of MoS2, NiCO3·2Ni(OH)2·4H2O, and Al2O3 precursors, followed by annealing under a H2 atmosphere, which does not require a sulfurization process compared to traditional preparation methods. The influence of the annealing temperature and the type of Al2O3 precursor on the interactions between MoS2 and Al2O3 were studied using X-ray fluorescence spectroscopy, X-ray diffraction, N2 adsorption–desorption, Raman spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The results indicated an increase in the number of stacked layers of the MoS2 catalyst, accompanied by a decrease in the degree of decoration of Ni atoms onto MoS2 nanoslabs, as a result of the strengthened MoS2–Al2O3 interaction. Subsequently, the efficiency of hydrodesulfurization (HDS) was evaluated using dibenzothiophene as a representative reactant, while establishing a correlation between the structure of the catalyst and its performance. The catalysts, using pseudo-boehmite as the precursor and calcined at 500 °C, synthesized by calcining pseudo-boehmite as the precursor for Al2O3 at a temperature of 500 °C and possessing suitable metal–support interactions, exhibited a reduced number of MoS2 stacking layers and lateral dimensions, along with an optimal decoration degree of Ni atoms, thereby resulting in the highest level of HDS activity.