Unsupported Sulfide Catalysts Research Articles

Competitive Hydrodechlorination and Hydrodeazotization on Unsupported Sulfide Catalysts Synthesized in Situ

Competitive Hydrodechlorination and Hydrodeazotization on Unsupported Sulfide Catalysts Synthesized in Situ

Hydrodechlorination of 1,4-Dichlorobenzene over Unsupported Sulfide Catalysts

Hydrodechlorination of 1,4-Dichlorobenzene over Unsupported Sulfide Catalysts

Effect of Zr on catalytic performance of unsupported Ni(Zr)Mo and Ni(Zr)W sulfide catalysts for quinoline hydrodenitrogenation

Effect of Zr on catalytic performance of unsupported Ni(Zr)Mo and Ni(Zr)W sulfide catalysts for quinoline hydrodenitrogenation

Preparation of highly active unsupported Ni–Si–Mo catalyst for the deep hydrogenation of aromatics

Preparation of highly active unsupported Ni–Si–Mo catalyst for the deep hydrogenation of aromatics

Hydrogenation of Polymeric Petroleum Resins in the Presence of Unsupported Sulfide Catalysts Synthesized from Water-Soluble Precursors

Unsupported nickel–molybdenum sulfide hydrogenation catalysts are ex situ synthesized from precursor-aqueous-solution-in-decalin emulsions. A comparative analysis of the activity of the synthesized catalysts and the GO-38 commercial supported catalyst in polymeric petroleum resin hydrogenation is conducted. It is shown that the activity of the synthesized catalysts is higher than the activity of the supported catalyst at an identical concentration of the active metal in the reaction medium. The effect of the type and concentration of the emulsifier on the size of the emulsion droplets and the catalytic activity of the resulting catalyst is studied. It is shown that polymeric petroleum resins can be used instead of synthetic surfactants as an emulsifier in catalyst synthesis. An optimum Mo/Ni ratio (1/0.25) that provides the maximum degree of hydrogenation (100 and 78% for olefinic and aromatic moieties, respectively) is found. Catalyst activity varies only slightly after reuse in two or three runs; further, activity in the hydrogenation of aromatic moieties decreases, while activity in the hydrogenation of double bonds remains unchanged; in this case, the degree of dispersion does not change.

Promoted catalysts for hydrogenation of bicyclic aromatic hydrocarbons obtained in situ from molybdenum and tungsten carbonyls

Promoted Мo and W catalysts have been prepared in situ via thermal decomposition of precursors, oil-soluble salts Mo(CO)6, W(CO)6, С°C16H30O4, and NiC16H30O4. TiO2, Al2O3, and ZrO(NO3)2 · 6H2O have been used as the acidic additives. Also, Mo and W unsupported sulfide catalysts have been prepared in the presence of elemental sulfur as the sulfiding agent. The catalysts have been characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The activity of the catalysts prepared in situ has been evaluated in the hydrogenation reaction of bicyclic aromatic hydrocarbons by the example of model mixtures of 10% solutions of naphthalenes (unsubstituted naphthalene, 1- and 2-methylnaphthalenes, and 1,5- and 2,3-dimethylnaphthalenes) in n-hexadecane. The effect of the precursor/acidic oxide ratio on the activity of the formed catalyst has been found. Hydrogenation of bicyclic aromatic hydrocarbons has been conducted at a hydrogen pressure of 2 and 5 MPa and a temperature of 380 and 400°C for 2 h. Hydrogenation of the unsubstituted aromatic ring has been preferable due to the absence of steric hindrances. The degree of conversion of n-hexadecane under the reaction conditions has been 1.5–7.5% depending on the reaction temperature. It has been found that the activity of the sulfided catalyst in the conversion of 1- and 2-methylnaphthalenes is inferior to the activity of the unsulfided analogue, while partial replacement of TiO2 by Al2O3 results in a decrease in the conversion of the substrates as opposed to the unsulfided catalysts, in which the use of nanocrystalline Al2O3 promotes an increase in the conversion.

Preparation of highly active unsupported nickel–zinc–molybdenum catalysts for the hydrodesulfurization of dibenzothiophene

Preparation of highly active unsupported nickel–zinc–molybdenum catalysts for the hydrodesulfurization of dibenzothiophene

Transformation of Mo and W thiosalts into unsupported sulfide catalysts: A temperature dependent in-situ spectroscopic investigation

Transformation of Mo and W thiosalts into unsupported sulfide catalysts: A temperature dependent in-situ spectroscopic investigation

Production of Clean Fuel Utilizing the Unsupported Sulfide Catalysts

The sulfur specification for diesel fuel has been tightened exponentially over the years. In this manuscript, the unsupported Ni-Mo (-W) sulfide hydrotreating catalysts were prepared to produce the clean diesel fuel with ultra-low sulfur, nitrogen, and aromatics contents. The X-ray Diffraction (XRD), Low Temperature N2Adsorption (BET method), and High Resolution Transmission Electron Microscope (HRTEM) were applied to characterize the as-prepared catalysts. The characterization results indicate that the unsupported Ni-Mo (-W) hydrotreating catalyst have high specific surface area, large pore volume, high MoS2or WS2stacking layers, and large MoS2or WS2crystal length. The catalysts were evaluated in the micro-reactor using FCC diesel fuel as the raw material. The evaluation results reveal that the unsupported Ni-Mo (-W) catalysts have excellent hydrogenation performance. Utilizing the unsupported Ni-Mo (-W) sulfide catalysts is an efficient method to produce clean diesel fuel. Keywords: clean fuel; Ni-Mo (-W) sulfide; catalyst; hydrogenation

Amorphous unsupported Ni–Mo sulfide prepared by one step hydrothermal method for phenol hydrodeoxygenation

Amorphous unsupported Ni–Mo sulfide prepared by one step hydrothermal method for phenol hydrodeoxygenation

97/02723 Recent advances and future prospects for direct coal liquefaction process development

97/02723 Recent advances and future prospects for direct coal liquefaction process development

Unsupported Ni‐mo Sulfide Catalysts: Relation Between the HDS and Hydrogenation Activities and Some Structural Properties

AbstractA series of unsupported sulfide catalysts containing nickel and molybdenum (with variable atomic ratio a Ni/Ni + Mo) was prepared using a variant of the H.S.P. method which promotes an “intimate contact” between the metallic ions. These catalysts show good activities in the dibenzothiophene hydrodesulfurization (under atmospheric or high pressure) and in the biphenyl hydrogenation. For the two reactions, the maximum of synergy is observed for a about 0.7.X‐ray diffraction shows that for a < 0.3, only the MoS2 type phase is detected (before and after catalytic test). For higher values of a, nickel sulfide initially present under the NiS2 and NiSβ phases form, is converted into the Ni3S2 phase by catalytic working.The variations, in terms of a, of the specific area, of the stoichiometric ratio S/Ni + Mo' of the c parameter of the MoS2 type phase, of the TPR spectra shape, show the existence of a mixed phase “Mo ‐ Ni ‐ S” of the same crystallo‐graphic type than MoS2. The presence of this phase would induce an increase of the HDS and hydrogenation properties of the catalyst without explaining the position of the synergy maximum.