ChemInform Abstract: Morphology and Activity of MoS2 on Various Supports: Genesis of the Active Phase.

Pratt, Kerry C.; Sanders, J. V.; Christov, V.

doi:10.1002/chin.199044024

Cited by 8 publications

(14 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This phase consists of rounded crystals, about 20 nm in size, linked in short chains and forming open tubular clusters several micrometers in size. Electron diffraction patterns contain spacings consistent with those of A12(Mo04)3, but with additional spacings, while XRD spectra show reflections 8tting the pattern expected from Moo3 (38). This phase was also observed in a 16% Moo3-8% NiO-l.5% P/Si02-A1203 catalyst (FIG.…”

Section: Figmentioning

confidence: 56%

“…The intrinsic HDS rate (per Mo atom) for Mo/Ti02 is undoubtedly superior (1.6 to 4.4 times, depending on test conditions) to that of comparable Mo/Al2O3 catalysts (38,87,128,132). Molybdenum deposited on alumina coated by 25 wt%Ti02 shows the same trend (133).…”

Section: Preparation and Properties Of Titania-supported Catalystsmentioning

confidence: 58%

“…At 300"C, mobile species are formed on hexagonal Moo3 crystallites and migrate across the silica surface to form amorphous multilayers oriented with their basal planes parallel to the silica surface (75). Reduction-sulfidation of a 10% Mo03/Si02 catalysts (0.50 mg Mo/m2, X-Ray crystallite diameter 25 nm) leads to appearance of Mo metal along with large crystallites of MoS2 (76), in the same manner than Moo3 in loose interaction with alumina (38).…”

Section: Preparation Structure and Actlvity Of Silica-supported Hdt mentioning

confidence: 97%

“…The sulfidation process is accompanied by some uncovering of the Al2O3 surface (33,36,37). Depending seemingly on sulfidation conditions, the MoS2 slabs are found oriented normal (38) or parallel (39, 40) to the support surface. This suggests that the preferential orientation of the MoS2 slab will depend on the density and relative proportion of anchoring AI-0-Mo and AI-S-Mo bonds.…”

Section: Physlcocherntcal Properties Of Alumhamentioning

confidence: 98%

See 3 more Smart Citations

A Review of Support Effects on the Activity and Selectivity of Hydrotreating Catalysts

Luck¹

1991

Bulletin des Soc Chimique

116

View full text Add to dashboard Cite

INTRODUCTIONThe hydroprocessing technology was first developed in Germany by BASF in the 1920s, for hydrogenation of brown coal tar in one step into gasoline without coke formation. It was found that cobalt, molybdenum and tungsten sulfides were especially active catalysts (1). Later a low-temperature " T H " process was developed for the same reaction, using activated alumina supported catalysts containing either 10% Mo03-3% NiO or 27% WS23% NiS. The very same compositions are still used today in many commercial hydrotreating (HDT) catalysts! During the development of these catalysts, the effect of various oxide supports on the cracking of gas oil was studied. The following order of cracking activity was found :

show abstract

Section: Figmentioning

confidence: 56%

Section: Preparation and Properties Of Titania-supported Catalystsmentioning

confidence: 58%

Section: Preparation Structure and Actlvity Of Silica-supported Hdt mentioning

confidence: 97%

Section: Physlcocherntcal Properties Of Alumhamentioning

confidence: 98%

See 2 more Smart Citations

A Review of Support Effects on the Activity and Selectivity of Hydrotreating Catalysts

Luck¹

1991

Bulletin des Soc Chimique

116

View full text Add to dashboard Cite

show abstract

“…Ni-MoS2/ZrO2 was chosen as catalyst, as promotion by nickel previously has been shown to be slightly superior to cobalt promotion for HDO purposes [9,25] and ZrO2 was previously found as a suitable support for HDO [31][32][33][34][35] and does apparently not suffer from the instability in high concentration of water, as reported for the conventionally used -Al2O3 support for hydrotreating catalysts [9,36,37].…”

Section: Introductionmentioning

confidence: 99%

Deactivation of Ni-MoS2 by bio-oil impurities during hydrodeoxygenation of phenol and octanol

Mortensen

Gardini

Damsgaard

et al. 2016

Applied Catalysis A: General

View full text Add to dashboard Cite

Deactivation of Ni-MoS2 by bio-oil impurities during hydrodeoxygenation of phenol and octanol, Applied Catalysis A, General http://dx.doi.org/10. 1016/j.apcata.2016.06.002 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Graphical abstractHighlights  Impurities as Cl, S, and K found in bio-oil will deactivate or inhibit MoS2-type catalyst by competing for the active sites  MoS2-based catalysts will produce sulfur containing hydrocarbons during HDO, but these can be removed again if a sufficiently high residence time is used enabling desulfurization of the product  Chlorine binds more strongly to the active sites of MoS2 based catalysts compared to H2O and H2S, while K irreversibly deactivates the catalyst 3 AbstractThe stability of Ni-MoS2/ZrO2 toward water, potassium, and chlorine containing compounds during hydrodeoxygenation (HDO) of a mixture of phenol and 1-octanol was investigated in a high pressure gas and liquid continuous flow fixed bed setup at 280°C and 100 bar. To maintain the stability of the catalyst, sufficient co-feeding of a sulfur source was necessary to avoid oxidation of the sulfide phase by oxygen replacement of the edge sulfur atoms in the MoS2 structure. However, the addition of sulfur to the feed gas resulted in the formation of sulfur containing compounds, mainly thiols, in the oil product if the residence time was too low. At a weight hourly space velocity (WHSV) of 4.9 h -1 the sulfur content in the liquid product was 980 ppm by weight, but this could be decreased to 5 ppm at a WHSV of 1.4 h -1 . A high co-feed of sulfur was needed when water was present in the feed and the H2O/H2S molar ratio should be below ca. 10 to maintain a decent stability of the catalyst. Chlorine containing compounds caused a reversible deactivation of the catalyst when co-fed to the reactor, where the catalytic activity could be completely regained when removing it from the feed. Commonly, chlorine, H2O, and H2S all inhibited the activity of the catalyst by competing for the active sites, with chlorine being by far the strongest inhibitor and H2S and H2O of roughly the same strength. Dissimilar, potassium was a severe poison and irreversibly deactivated the catalyst to <5% degree of deoxygenation when impregnated on the catalyst in a stoichiometric ratio relative to the active metal. This deactivation was a result of adsorption of potassium on the edge vacancy sites of the MoS2 slabs.

show abstract

HDS AND HDN ACTIVITY AND CHARACTERIZATION OF NiMo ‐USY ZEOLITE CATALYSTS

Arias

Cambra

Güemez

et al. 1995

Bulletin des Soc Chimique

View full text Add to dashboard Cite

INTRODUCTIONHydrotreating reactions such as HDS, HDN and HC are usually conducted on mixed transition metal sulfides (Ni-Mo or NI-W) supported on carriers which are more or less acidic depending on the function to be promoted (1). As pointed out by Pratt et al.(2) the carrier has a marked effect on the specific activity of the sulfide catalysts. However, alumina, which is the most used carrier for this type of catalysts, offers only a moderate cracking activity and requires severe hydrotreating of the feedstock and compiete nitrogen removal. For these reasons, mixed sulfides dispersed on more acidic materials as silica-alumina or zeolites appear quite attractive. The incorporation of small amounts of zeolites into typical commercial hydrotreating catalysts led to significant activity improvement (3) because with thls type of modification were obtain more acidic catalysts than those supported on aiuminas or silica-aluminas. Such catalysts yield more desired products (light hydrocarbons and gasoiins) and are more resistant to poisoning by Sand N-containing compounds present in the feed (4,5).Many studies have been devoted to investigate the distribution of nickel and molybdenum in calcined HY zeolites (6-12), although only few dealt with their sulfided counterparts (13-16). However, these latter studies can be conclusive in the point that suifidation at high pressure conditions causes important structural modifications of the precursor phases, and even of the zeolite substrate. As it is well known, the USY zeolite has a very low ion exchange capacity which limits the feasibility to obtain metal-loaded zeolite catalysts with highly dispersed active ingredients across the crystal. As a consequence, the incorporation of both Ni and Mo components into USY zeolites usually leads to deposit the active ingredients at the external surface. As the dimensions of the channels of Y zeolites are too small as to facilitate the incorporation of voluminous anions of salts of Mo, non-conventional preparation methods have to be used to overcome these difficulties. Accordingly, this work was undertaken with the aim to compare catalytic

show abstract

ChemInform Abstract: Morphology and Activity of MoS2 on Various Supports: Genesis of the Active Phase.

Cited by 8 publications

References 1 publication

A Review of Support Effects on the Activity and Selectivity of Hydrotreating Catalysts

A Review of Support Effects on the Activity and Selectivity of Hydrotreating Catalysts

Deactivation of Ni-MoS2 by bio-oil impurities during hydrodeoxygenation of phenol and octanol

HDS AND HDN ACTIVITY AND CHARACTERIZATION OF NiMo ‐USY ZEOLITE CATALYSTS

Contact Info

Product

Resources

About