Skeletal Isomerization of Hexenes on Tungsten Oxide Supported on Porous α-Alumina

Logie, V.; Maire, G.; Michel, D.; Vignes, J.‐L.

doi:10.1006/jcat.1999.2600

Cited by 54 publications

(28 citation statements)

References 36 publications

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“…These peaks might be assigned to the stepwise reduction of WO 3 H 2 -TPR curves exhibit a marginal peak at 410-430°C, and no peak at 410-430°C is observed for 2 wt% WO 3 / SiO 2 catalyst. According to literature [20], the reduction peak at 850-885°C was attributed to the reduction of WO 3 , and the weak reduction peak at 410-430°C was assigned to the reduction of W species in octahedral coordination [19,21]. Besides, the 410-430°C peak shifts to lower temperature with increasing W loading, reflecting an improved reducibility of dispersed species.…”

Section: Characterization Of Catalystsmentioning

confidence: 98%

Effect of tungsten oxide loading on metathesis activity of ethene and 2-butene over WO3/SiO2 catalysts

Zhao

Chen

Gao

et al. 2009

Transition Met Chem

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The metathesis of ethene and 2-butene to propene was studied over WO 3 /SiO 2 catalysts with various WO 3 loadings (2, 4, 8, 12, 16, and 24 wt%). The 2-butene conversion and propene selectivity increased greatly with WO 3 loading increasing from 2 to 8 wt%, reached maximum at 8-12 wt% WO 3 loading, and then decreased when the WO 3 loading was higher than 12 wt%. From the above results and taking the economics into account, the optimal amount of WO 3 loading was *8 wt%. The catalysts were characterized by physico-chemical and spectroscopic techniques to elucidate the effect of different tungsten oxide loadings on the metathesis reactivity of ethene and 2-butene. The characterization data indicated that three types of tungsten species (i.e., surface tetrahedral tungsten species, surface octahedral polytungstate species, and WO 3 crystallites) were present in the catalysts. It was found that WO 3 was not the active centers, and surface tetrahedral tungsten species might be more active than octahedral polytungstate species in metathesis reaction. The reduced form of tungsten species [W ?4 , W ?5 , and W ?(6-y) (0 \ y \ 1)] may be the suitable state of W species acting as metathesis active centers.

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Section: Characterization Of Catalystsmentioning

confidence: 98%

Effect of tungsten oxide loading on metathesis activity of ethene and 2-butene over WO3/SiO2 catalysts

Zhao

Chen

Gao

et al. 2009

Transition Met Chem

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“…WO 2 (IV) ? W(0)] [22]. Two reduction peaks of CeO 2 at approximately 520 and 780°C are associated with the stepwise reduction.…”

Section: Tpr Analysismentioning

confidence: 98%

CeO2–WO3 Mixed Oxides for the Selective Catalytic Reduction of NO x by NH3 Over a Wide Temperature Range

et al. 2011

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A series of cerium-tungsten oxide catalysts was prepared by the co-precipitation method and was evaluated for the selective catalytic reduction of NO x by ammonia (NH 3 -SCR) over a wide temperature range. These catalysts were characterized by BET, XRD, XPS and H 2 -TPR analyses. The experimental studies demonstrated that, among cerium-tungsten oxides, CeO 2 -WO 3 with a Ce/W molar ratio of 3/2 exhibited the best activity toward NH 3 -SCR reactions, N 2 selectivity and SO 2 durability over a broad temperature range of 175-500°C at a space velocity of 47,000 h -1 . The strong interaction between Ce and W could be the main factor leading to the high activity of the CeO 2 -WO 3 mixed oxide catalyst.

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“…The H 2 -TPR profile of WO 3 exhibited three peaks at 893, 988, and1158 K, which might be assigned to the stepwise reduction of WO 3 [20,21]. The H 2 -TPR profile of the plain support only exhibited a very small peak at about 890 K, which was attributed to the reduction of Titanium [22]. For other catalysts, reduction peaks were between 800 and 900 K, meanwhile the reduction temperature shifted toward higher temperature, the intensity increased with increasing WO 3 loadings, and reached the maximum for 12% WO 3 /MTS-9.…”

Section: H 2 -Tprmentioning

confidence: 99%

Metathesis of butene to propene and pentene over WO3/MTS-9

Hua

Chen

Yuan

et al. 2011

Microporous and Mesoporous Materials

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Skeletal Isomerization of Hexenes on Tungsten Oxide Supported on Porous α-Alumina

Cited by 54 publications

References 36 publications

Effect of tungsten oxide loading on metathesis activity of ethene and 2-butene over WO3/SiO2 catalysts

Effect of tungsten oxide loading on metathesis activity of ethene and 2-butene over WO3/SiO2 catalysts

CeO2–WO3 Mixed Oxides for the Selective Catalytic Reduction of NO x by NH3 Over a Wide Temperature Range

Metathesis of butene to propene and pentene over WO3/MTS-9

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