Support effect for CoMoS and CoNiMoS hydrodesulfurization catalysts prepared by controlled method

• Highly promoted CoMoS supported catalysts were prepared from supported MoS2.
• The 4,6-DMDBT HDS catalytic activity of CoMoS was similar with NiMoS analogues.
• A pronounced hydrogenolysis behaviour was confirmed with Co-promoted catalyst on γ-alumina.
• Catalysts supported on silica presented higher intrinsic activities due to type-II site formation.
• CoNiMoS supported systems are less active and suffer from a bad accessibility to promoted sites.

CoMoS-supported catalysts were prepared by reacting Co-acetylacetonate hydrate complex onto four different oxides supported MoS2: γ-alumina, silica, zirconia and titania. This outstanding method allowed very high promoting levels to be reached on each support as confirmed by XPS characterization and spectral decomposition. These catalytic solids were tested in 4,6-DMDBT HDS and compared to the equivalent NiMoS supported systems prepared in the same way on the same supports. Furthermore, in order to better understand the behaviour of each promoter metal, mixed CoNiMoS supported solids were prepared using the same approach. The characterization and catalytic HDS experiments carried out with these catalysts demonstrated a higher reactivity between Co(acac)2 and MoS2 but a lower HDS catalytic activity was found for the CoNiMoS systems compared to the CoMoS and NiMoS analogues which suggest that some of the active sites became inaccessible.

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