Effect of pH on Activity of NiMo/Al2O3 Catalysts Prepared with Citric Acid in Simultaneous Hydrodesulfurization and Hydrodenitrogenation Reactions

Braggio, F.; Mello, Matheus Dorneles de; Magalhães, Bruno C.; Zotin, José Luiz; Silva, Mônica A. P.

doi:10.1007/s10562-016-1903-6

Cited by 12 publications

(9 citation statements)

References 49 publications

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“…There were also significant changes in product distribution because BP yield was favored over CHB (Figure b), indicating a stronger inhibition of HYD route. Hence, even though quinoline inhibits both DDS and HYD routes, the HYD sites are preferentially poisoned by the nitrogen compound, as already previously reported in the literature. ,− …”

Section: Resultssupporting

confidence: 73%

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Effects of Citric Acid Addition Method on the Activity of NiMo/γ-Al₂O₃ Catalysts in Simultaneous Hydrodesulfurization and Hydrodenitrogenation Reactions

et al. 2019

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Two NiMo catalysts were prepared by different methods using citric acid to assess the effects of preparation method on dibenzothiophene hydrodesulfurization (HDS) and simultaneous HDS and hydrodenitrogenation: co-impregnation and post-treatment. Characterization of oxide catalysts was performed by nitrogen physisorption, X-ray diffraction, and temperature-programmed sulfidation, while sulfided samples were characterized by temperature-programmed reduction (TPR-S) and NO chemisorption. The catalytic evaluation for HDS reaction was performed in a three-phase reactor, with and without quinoline. The direct desulfurization is the preferred route for the HDS of dibenzothiophene. The post-treatment method was more efficient in achieving higher catalytic activity than co-impregnation. Furthermore, TPR-S and NO chemisorption results show an enhancement in the density of active sites on the catalyst prepared by post-treatment, being more hydrogenating than the one synthesized by co-impregnation. Although the catalyst prepared by post-treatment was more inhibited by quinoline, it remained more active than the one synthesized by co-impregnation.

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Section: Resultssupporting

confidence: 73%

“…The sulfidation of both catalysts was investigated by TPS. Detailed procedures of all the characterization methods can be found elsewhere …”

Section: Methodsmentioning

confidence: 99%

Effects of Citric Acid Addition Method on the Activity of NiMo/γ-Al₂O₃ Catalysts in Simultaneous Hydrodesulfurization and Hydrodenitrogenation Reactions

et al. 2019

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“…To date, hydrodesulfurization (HDS) has been a general industrial technology for fuel oil desulfurization. The sulfur-containing compounds, e.g., dibenzothiophene (DBT), are usually catalytically removed through two main reaction pathways (as seen in Scheme 1: (i) direct C-S bond cleavage (the so-called direct desulfurization pathway, DDS), yielding the corresponding biphenyl (BP) product; (ii) initial hydrogenation followed by C-S bond rupture (the hydrogenation pathway, HYD), yielding first tetrahydrodibenzothiophene (THDBT) and then the corresponding cyclohexylbenzene product (CHB) [4,5]. The DDS pathway has an advantage in having less hydrogen consumption for desulfurization.…”

Section: Introductionmentioning

confidence: 99%

Complete Hydrodesulfurization of Dibenzothiophene via Direct Desulfurization Pathway over Mesoporous TiO2-Supported NiMo Catalyst Incorporated with Potassium

Song²,

Yue

et al. 2019

Catalysts

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Mesoporous TiO2 containing different potassium content was prepared from potassium titanate by mediating the pH value of the ion exchange, which was used as catalytic support to load NiMo for hydrodesulfurization of dibenzothiophene. The as-prepared samples were characterized by X-ray diffraction, N2 physical adsorption/desorption, temperature-programmed reduction, scanning electron microscope/energy dispersive X-ray mapping analysis, high resolution transmission electron microscopy, and pyridine-adsorbed Fourier transform infrared spectroscopy. The characterization results showed that NiO and MoO3 were well dispersed on mesoporous TiO2 with varying potassium content. A crystal NiMoO4 phase was formed on the TiO2 with relatively high potassium content, which could decrease the reduction temperature of oxidized active species. The evaluation results from the hydrodesulfurization displayed that as the potassium content of the catalyst increased, the dibenzothiophene conversion firstly increased and then slightly decreased when potassium content exceeded 6.41 wt %. By contrast, the direct desulfurization selectivity could continuously increase along with the potassium content of catalyst. Furthermore, the change in direct desulfurization selectivity of a TiO2-supported NiMo catalyst was independent of the reaction condition. The mesoporous TiO2-supported NiMo catalyst incorporated with potassium could have near both 100% of dibenzothiophene and 100% of direct desulfurization selectivity. According to the structure–performance relationship discussion, the incorporation of potassium species could benefit the formation of more sulfided active species on mesoporous TiO2. Moreover, excessive free potassium species may poison the active sites of the hydrogenation pathway. Both factors determined the characteristics of complete hydrodesulfurization of dibenzothiophene via a direct desulfurization pathway for potassium-incorporated mesoporous TiO2 supported NiMo catalysts.

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“…NiO and MoO 3 contents exhibit close values to the theoretical ones. Textural characterization indicates that the specific area of NiMo/Alu is similar to the original support (Alu), considering the intrinsic analysis error (approximately 10%) [29]. On the other hand, NiMo/HY catalyst presents a decrease of micropore area compared to the pure zeolite.…”

Section: Compositional Structural and Textural Propertiesmentioning

confidence: 96%

Impact of proximity between NiMoS and zeolitic HY sites on cyclohexene hydroconversion: An infrared operando study of sulfide catalysts

Santos

Zhao

Zotin

et al. 2021

Journal of Catalysis

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Effect of pH on Activity of NiMo/Al2O3 Catalysts Prepared with Citric Acid in Simultaneous Hydrodesulfurization and Hydrodenitrogenation Reactions

Cited by 12 publications

References 49 publications

Effects of Citric Acid Addition Method on the Activity of NiMo/γ-Al₂O₃ Catalysts in Simultaneous Hydrodesulfurization and Hydrodenitrogenation Reactions

Effects of Citric Acid Addition Method on the Activity of NiMo/γ-Al₂O₃ Catalysts in Simultaneous Hydrodesulfurization and Hydrodenitrogenation Reactions

Complete Hydrodesulfurization of Dibenzothiophene via Direct Desulfurization Pathway over Mesoporous TiO2-Supported NiMo Catalyst Incorporated with Potassium

Impact of proximity between NiMoS and zeolitic HY sites on cyclohexene hydroconversion: An infrared operando study of sulfide catalysts

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Effect of pH on Activity of NiMo/Al2O3 Catalysts Prepared with Citric Acid in Simultaneous Hydrodesulfurization and Hydrodenitrogenation Reactions

Cited by 12 publications

References 49 publications

Effects of Citric Acid Addition Method on the Activity of NiMo/γ-Al2O3 Catalysts in Simultaneous Hydrodesulfurization and Hydrodenitrogenation Reactions

Effects of Citric Acid Addition Method on the Activity of NiMo/γ-Al2O3 Catalysts in Simultaneous Hydrodesulfurization and Hydrodenitrogenation Reactions

Complete Hydrodesulfurization of Dibenzothiophene via Direct Desulfurization Pathway over Mesoporous TiO2-Supported NiMo Catalyst Incorporated with Potassium

Impact of proximity between NiMoS and zeolitic HY sites on cyclohexene hydroconversion: An infrared operando study of sulfide catalysts

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Effects of Citric Acid Addition Method on the Activity of NiMo/γ-Al₂O₃ Catalysts in Simultaneous Hydrodesulfurization and Hydrodenitrogenation Reactions

Effects of Citric Acid Addition Method on the Activity of NiMo/γ-Al₂O₃ Catalysts in Simultaneous Hydrodesulfurization and Hydrodenitrogenation Reactions