Sulfidation Study of Molybdenum Oxide Using MoO3/SiO2/Si(100) Model Catalysts and Mo-IV3-Sulfur Cluster Compounds

Muijsers, J. C.; Weber, Th.; Hardeveld, R.M. van; Zandbergen, H.W.; Niemantsverdriet, J.W.

doi:10.1006/jcat.1995.1335

Cited by 207 publications

(120 citation statements)

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“…The Mo (3d) spectra reveal exactly the same oxidation state (Mo ?VI ? Mo ?V ) for both non-activated catalysts (Muijsers et al 1995). However, the trend is not the same for activated catalysts; activation reduces the Mo species over c-Al 2 O 3 to Mo ?IV , while the MgO-supported catalyst not only shows no such reduction, but also shows extra oxidation compared with its non-activated counterparts.…”

Section: Xps Resultsmentioning

confidence: 89%

“…Consequently, the use of bulk characterization techniques is not adequate in determining the chemical state of Mobased catalysts. XPS provides interesting information concerning the state of highly dispersed catalysts and is a technique that has been used in similar studies to determine the extent and state of Mo sulfidation in the presence (Coulier et al 2002;Fontaine et al 2010) and absence (Muijsers et al 1995;Saih and Segawa 2003) of promoter over different supports (Muijsers et al 1995;Roukoss et al 2009). …”

Section: Xps Resultsmentioning

confidence: 99%

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Comparison of Mo/MgO and Mo/γ-Al2O3 catalysts: impact of support on the structure and dibenzothiophene hydrodesulfurization reaction pathways

Heidarinasab

Soltanieh

Ardjmand

et al. 2016

Int. J. Environ. Sci. Technol.

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The MgO and P 2 O 5 -promoted c-Al 2 O 3 supports with alkaline and acidic natures, respectively, were prepared, impregnated with Mo atoms, and compared for dibenzothiophene (DBT) hydrodesulfurization (HDS) reaction. Ultraviolet spectroscopy and the principal component analysis were used to identify the impact of the supports on the reaction pathways. The catalysts were characterized by BET surface analysis, X-ray diffraction, temperature-programmed reduction, Fourier transform infrared, and X-ray photoelectron spectroscopy. The cAl 2 O 3 -supported catalyst favors the hydrogenation pathway relative to the MgO-supported catalyst, which facilitates the direct desulfurization route. The different performance was attributed to the dissimilar Mo phases that emerged during the activation procedure. The activation under sulfo-reductive condition changed the Mo atoms on c-Al 2 O 3 support into the sulfide phase while extra oxidation took place for the MgO-supported catalyst. The migration and consumption of loosely bonded bulk oxygen atoms with under-coordinated Mo atoms on the MgO support were introduced as a possible reason for such extra oxidation. DFT calculations predicted an interaction between the Mo/MgO catalyst and DBT via the electron donation from the catalyst oxygen atoms to the aromatic rings, resulting in weakening and breaking of the C-S bonds. In spite of the higher resistance of the MgO-supported catalyst toward coking and its superior activity, its lower hydrogenation capability suggested using a dualfunction catalyst. Accordingly, two catalysts were mixed and the synergism was observed in the HDS reaction of thiophene.

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Section: Xps Resultsmentioning

confidence: 89%

Section: Xps Resultsmentioning

confidence: 99%

Comparison of Mo/MgO and Mo/γ-Al2O3 catalysts: impact of support on the structure and dibenzothiophene hydrodesulfurization reaction pathways

Heidarinasab

Soltanieh

Ardjmand

et al. 2016

Int. J. Environ. Sci. Technol.

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“…MoO 3 has a structure formed by MoO 3 octahedra linked together to form bi-layers, which are connected between them by Van Der Walls forces [28,29]. It was shown [26,27] that the sulphidation process of MoO 3 starts by substituting the O ions at the outer surfaces of the bi-layers by S ions. The latter subsequently diffuse and substitute the internal oxygen ions in the bi-layers.…”

Section: Contributed Articlementioning

confidence: 98%

“…This reaction, used in the hydrodesulfurization of oil since many years [25], has been studied with various experimental methods [26,27]. MoO 3 has a structure formed by MoO 3 octahedra linked together to form bi-layers, which are connected between them by Van Der Walls forces [28,29].…”

Section: Contributed Articlementioning

confidence: 99%

Hot‐wire vapor deposition of amorphous MoS₂ thin films

Papadimitropoulos

Vourdas

Kontos

et al. 2015

Phys. Status Solidi C

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Amorphous, as shown by X‐ray diffraction measurements, MoS2 films (a‐MoS2) were deposited by heating a molybdenum wire at temperatures between 500 and 700 °C in H2S at 1 Torr. As shown by Scanning Electron Microscopy measurements, the morphology of samples depends significantly on the filament temperature; at low temperature samples are homogeneous and smooth, at intermediate temperatures they exhibit a granular microstructure and at high temperatures a columnar one. X‐ray photoelectron spectroscopy measurements have shown S/Mo ratios in films varying between 2.5 and 1.5 dependent on filament temperature. Films also contain oxygen at atomic contents of 8 to 12%. As shown by XPS and Raman spectroscopy, at a filament temperature of 600 °C films are mainly composed of MoS2 also containing oxygen at an atomic ratio of 8%. Spectroscopic ellipsometry measurements made on a‐MoS2 films have shown that their band gap is of the order of 1.4 eV, slightly higher than that for the bulk crystalline material. Photoluminescence spectroscopy measurements have shown that samples exhibit a doublet of peaks at 2.8 and 3 eV blue shifted relatively to MoS2 samples composed of one or two mono‐layers. The above indicate that the electronic structure of crystalline atomic‐layer thick MoS2 is preserved in a‐MoS2 films. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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“…Model systems of molybdenum oxide catalysts have been extensively studied with techniques as XPS and infrared emission spectroscopy [10,11,12,13] which have to be performed under ultra-high-vacuum conditions. Although Raman spectroscopy showed to be an indispensable tool to study the different phases and coordination of Mo-species in catalysts the extremely low loading of active phase in model systems makes it very difficult to obtain Raman spectra with conventional Raman spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Potential of UV–Raman Spectroscopy for Characterization of Sub-monolayer MoO_xModel Catalysts at Ambient Pressure

et al. 2004

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UV-Raman spectroscopy is demonstrated to be a valuable tool to study molybdenumoxide model catalysts at ambient pressure while visible light Raman yields no information. UV-Raman offers the possibility to characterize MoO x /Al 2 O 3 /Si and MoO x /SiO 2 / Si model systems with sub-monolayer loading of MoO x even though the surface area of a Si-wafer is much lower than that of a bulk support. Anchoring of MoO x onto Al 2 O 3 /Si and SiO 2 /Si results in similar molybdenum oxide compounds as for bulk catalysts.

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Sulfidation Study of Molybdenum Oxide Using MoO3/SiO2/Si(100) Model Catalysts and Mo-IV3-Sulfur Cluster Compounds

Cited by 207 publications

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Comparison of Mo/MgO and Mo/γ-Al2O3 catalysts: impact of support on the structure and dibenzothiophene hydrodesulfurization reaction pathways

Comparison of Mo/MgO and Mo/γ-Al2O3 catalysts: impact of support on the structure and dibenzothiophene hydrodesulfurization reaction pathways

Hot‐wire vapor deposition of amorphous MoS₂ thin films

Potential of UV–Raman Spectroscopy for Characterization of Sub-monolayer MoO_xModel Catalysts at Ambient Pressure

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Sulfidation Study of Molybdenum Oxide Using MoO3/SiO2/Si(100) Model Catalysts and Mo-IV3-Sulfur Cluster Compounds

Cited by 207 publications

References 0 publications

Comparison of Mo/MgO and Mo/γ-Al2O3 catalysts: impact of support on the structure and dibenzothiophene hydrodesulfurization reaction pathways

Comparison of Mo/MgO and Mo/γ-Al2O3 catalysts: impact of support on the structure and dibenzothiophene hydrodesulfurization reaction pathways

Hot‐wire vapor deposition of amorphous MoS2 thin films

Potential of UV–Raman Spectroscopy for Characterization of Sub-monolayer MoOxModel Catalysts at Ambient Pressure

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Product

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Hot‐wire vapor deposition of amorphous MoS₂ thin films

Potential of UV–Raman Spectroscopy for Characterization of Sub-monolayer MoO_xModel Catalysts at Ambient Pressure