MOR nanosheet assemblies supported NiW catalysts in the hydrodesulfurization of the 4,6-DMDBT: Effect of Ni/W ratio on the catalytic performance

Effect of the Co/Mo Ratio on the Morphology and Activity of the CoMo Catalyst Supported on MgO Nanosheets in Dibenzothiophene Hydrodesulfurization

“…It has been suggested that the high sulfidation degree leads to high HDS activity because of more occurrences of the formation of the MoS 2 active phase. 39,61 However, the CoMo/NA-MgO-0.5 catalyst showed higher catalytic activity than that of the CoMo/γ-Al 2 O 3 catalyst in spite of its lower sulfidation degree than that of the CoMo/γ-Al 2 O 3 catalyst.…”

“…On the other hand, the slab length and stacking of the MoS 2 crystallites were slightly affected by the Co/Mo ratio of CoMo/NA-MgO- x catalysts (Table ). However, many studies report that the promoter could change the active phase morphology, which could increase the particle length and stacking number. ,, In this work, the addition of the Co promoter led to a slight reduction in both the slab length and stacking of the MoS 2 crystallites, and the CoMo/NA-MgO catalyst with the Co/Mo ratio of 0.5 presented the MoS 2 crystallites with the lowest average length (5.09) and stacking number (1.16). A further increase of the Co/Mo ratio caused a little increase in the slab length and stacking of the MoS 2 crystallites.…”

“…A further increase of the Co/Mo ratio caused a little increase in the slab length and stacking of the MoS 2 crystallites. A possible explanation for the inconsistent results in the literature is the use of supports with different surface chemical properties, which could have an influence on the state of the precursors of Mo oxides and Co–Mo interaction. ,, Most of research work of the modification of metal sulfide catalysts was focused on the alumina support with the dominant Lewis acid sites. Meanwhile, the employed NA-MgO here was basic in nature, and there were large amounts of basic sites on its surface.…”

“…The strong metal–support interaction leads to difficult sulfidation of the MoO x species and the formation of the low-stacking MoS 2 particles. , In agreement with this, the CoMo/NA-MgO-0.5 catalyst showed a lower sulfidation degree of the MoO x species and less stacking MoS 2 crystallites than those of the CoMo/γ-Al 2 O 3 catalyst after catalyst activation by the H 2 –H 2 S mixture, which was illustrated by the XPS and TEM data. It has been suggested that the high sulfidation degree leads to high HDS activity because of more occurrences of the formation of the MoS 2 active phase. , However, the CoMo/NA-MgO-0.5 catalyst showed higher catalytic activity than that of the CoMo/γ-Al 2 O 3 catalyst in spite of its lower sulfidation degree than that of the CoMo/γ-Al 2 O 3 catalyst.…”

Importancia del estudio de catalizadores para la reducción de compuestos organoazufrados en gasolinas y diésel

“…Además, el uso de agentes quelantes permiten que las especies de Ni y W tengan una mejor sulfuración para formar las fases activas, ya que las especies de Ni y W se sulfuran a diferente temperatura (Scheffer et al, 1990). La hidrodesulfuración de molécula refractaria, el 4,6-dimetidibenzotiofeno, requirió una relación molar Ni/W de 0.55 utilizando EDTA como agente quelante en catalizadores NiW soportados en zeolitas (Zhang et al, 2018). Mientras que en reacciones de hidrodesulfuración con tiofeno, que es la molécula modelo menos impedida estéricamente, usando un catalizador NiW soportado en Al2O3 la relación óptima de Ni/Ni + W fue de 0.41 (Zuo et al, 2004a).…”