Dependence of Morphology, Dispersion and Hydrodesulfurization Performance of Active Phases in NiMo/SBA‐15 on Loading Method

Abstract

With the aim of exploring the dependence of morphology, dispersion and hydrodesulfurization (HDS) activity of active phases over SBA‐15 on loading method, four NiMo/SBA‐15 catalysts have been prepared by two different Mo introduction strategies with varying MoO3 contents (13 and 19 wt.% in each approach, respectively). One of the approaches is the conventional incipient wetness impregnation (IM) and the other is a new‐proposed Mo‐based inorganic‐organic hybrid nanocrystals as the precursor with hydrothermal‐assisted (HA) loading method. The results show that metal species are severely aggregated at a high concentration by IM method, leading to the poorly distributed MoS2 slabs with large sizes and ultra‐high stacking layers. While in case of the HA approach, the organic molecules surrounding the Mo species can isolate Mo species effectively to prevent them from aggregation and greatly improve the dispersion of active phases, even at high MoO3 loadings. Therefore, the HDS activity is improved as increasing the amounts of MoO3 for the catalyst prepared with HA method because of the more active sites accessible to the reactants, however, HDS activity is decreased for the catalyst acquired by the IM method due to the serious metal aggregation. It is demonstrated that the HA method is favorable for the better dispersion of active phases over SBA‐15 with the help of organic molecules leading to the effective MoS2 morphology with remarkably enhanced catalytic activity, and such superiority of the HA approach is more prominent at high MoO3 loadings.

3D Printing Technique Fortifies the Ultradeep Hydrodesulfurization Process of Diesel: A Journey of NiMo/Al2O3-MMT

“…It has been reported that the specific surface area of carrier significantly influences the dispersion of active metal oxides on the heterogeneous HDS catalyst surface. , Therefore, to further probe the effect of MMT addition on the dispersion of active metal oxides on the surfaces of NiMo/MMT, NiMo/Al 2 O 3 , NiMo/Al 2 O 3 -MMT, and 3D-NiMo/Al 2 O 3 -MMT catalysts, UV–vis DRS was performed. Figure displays that the typical adsorption bands corresponding to ligand charge transferring to the metal (O 2– → Mo 6+ ) at 200–350 nm are exhibited by all catalysts, where the characteristic adsorption bands at 220–250, 270–320, and above 320 nm are attributed to the adsorption of tetrahedral molybdate, octahedral coordination Mo–O–Mo bridge bond, and MoO 3 particles, respectively .…”

Mesoporous Gamma‐Alumina‐Supported Mo Catalysts: Effect of Calcination Temperature

“…Indeed, the catalytic activities of MoS 2 -based catalyst are mainly dependent on the dispersion of the active phase and the proportion of edge to rim sites, as well as the stacking of MoS 2 slabs. [14][15][16] Therefore, controlling the morphology of MoS 2 is crucial for obtaining high-activity HDS catalysts. Various methods have been taken to improve the catalytic performance of MoS 2based catalysts, such as the addition of active promoters (Ni and Co) and the optimization of sulfidation conditions (sulfiding agents).…”

Ultrasmall Ni-Promoted WS2 Nanocatalyst with Enhanced Number of Edge Atoms for Hydrodesulfurization

“…In recent years, the availability of light crude oil with low sulfur content is decreasing, whereas the permissible limit of sulfur in diesel is continuously being reduced due to environmental hazards. − Commonly, Ni/Co-promoted Mo­(W)­S 2 catalysts have been used in the hydrodesulfurization (HDS) catalytic process. However, the currently available catalysts are not active enough to reduce the sulfur content to meet the present/future regulations, which has propelled the researchers toward the development of highly active hydrodesulfurization (HDS) catalysts. − It should be noted that the choice of HDS catalysts mainly depends upon the feed quality and product specifications .…”