Break-in Behavior of a Tungsten Oxide on Silica Catalyst in Propylene Disproportionation

Gangwal, S.K.; Fathikalajahi, J.; Wills, G. B.

doi:10.1021/i360063a009

Cited by 14 publications

(5 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As can be seen in Fig. 3, there is an approximately 1.5 h break-in period as reported in previous studies [43,50,51]. Thomas et al [43] observed such a period on WO 3 /SiO 2 catalyst, which is attributed to the gradual formation of the active W-carbene species on the catalyst.…”

Section: Benchmarking Experiments With Wo 3 -Impregnated Silicas As Csupporting

confidence: 80%

Enhanced metathesis of ethylene and 2-butene on tungsten incorporated ordered mesoporous silicates

Ramanathan

Snavely

et al. 2016

Applied Catalysis A: General

View full text Add to dashboard Cite

Tungsten-incorporated 3D mesoporous silicates, W-KIT-6, W-KIT-5, and W-SBA-16 catalysts, outperform supported tungsten oxide catalysts (WO 3 /SiO 2 and WO 3 /KIT-6) for the metathesis of ethylene and 2-butene to propene at 450°C. All catalysts exhibit steady activity and stability during 7 h runs in a fixed-bed reactor. Furthermore, on all mesoporous catalysts, a maximum propylene yield was obtained at an optimum W loading at which the catalyst acidity is also maximum. Slightly delayed addition of the W source during the one-pot synthesis protocol markedly improves the propene yield on W-KIT-6 catalyst. XPS results conclusively show that this enhancement is due to preferential enrichment of active W species on the catalyst surface. Extended runs lasting five days reveal very little loss of activity even which is easily recovered by calcination in air.

show abstract

Section: Benchmarking Experiments With Wo 3 -Impregnated Silicas As Csupporting

confidence: 80%

Enhanced metathesis of ethylene and 2-butene on tungsten incorporated ordered mesoporous silicates

Ramanathan

Snavely

et al. 2016

Applied Catalysis A: General

View full text Add to dashboard Cite

show abstract

“… 9 Many factors affect catalytic activity including the content of tungsten oxide loading, 10 oxidation state of tungsten species, 11 conditions of preparation, 12–14 properties of support, 8,15 and pretreatment conditions. 16,17 Experimental studies have reported that the tetrahedral tungsten oxide species are the active sites for metathesis 2,18 and that WO 3 crystals are not active in metathesis and catalyst sites should be contained in the amorphous surface. 19 …”

Section: Introductionmentioning

confidence: 99%

Effect of pretreatment atmosphere of WO_x/SiO₂catalysts on metathesis of ethylene and 2-butene to propylene

et al. 2018

View full text Add to dashboard Cite

The effect of a gas pretreatment atmosphere (pure N 2 , pure H 2 and mixed H 2 /N 2 ) on the metathesis reaction between ethylene and 2-butene to propylene over calcined and non-calcined WO 3 /SiO 2 catalysts was investigated. The non-calcined catalysts exhibited higher activity than the calcined catalysts under different gas pretreatment atmospheres. The non-calcined catalyst with the use of pure H 2 pretreatment showed the highest catalytic performances. As revealed by various characterization results from N 2 physisorption, XRD, XPS, TEM, SEM-EDX, UV-Vis, Raman, H 2 -TPR, and NH 3 -TPD techniques, the WO 2.83 phase occurring from the H 2 pretreatment of the non-calcined catalyst played an important role on the high activity of the catalyst. In addition, better tungsten dispersion, higher isolated surface tetrahedral tungsten oxide species, and W 5+ species were obtained on the H 2 -treated non-calcined WO 3 /SiO 2 catalyst.

show abstract

“…yield of detergent-range alkenes Y C 2 [%] yield of ethylene Y C 3 [%] yield of propylene Figure 9. C 10 -C 16 yield surface plots of feed composition and space time at a fixed temperature of 440°C; feed composition and temperature at a fixed space time of 300 g min mol -1 ; space time and temperature at a fixed feed composition of 70 mol % 1-hexene for (a) standard 8 wt % WO 3 /SiO 2 , (b) 0.1 wt % K-doped, and (c) 0.5 wt % K-doped catalysts.…”

Section: Discussionmentioning

confidence: 99%

“…The reaction involves the formal cleavage of the carbon double bonds in two alkene molecules followed by the redistribution of the alkyl fragments: 2CH 2 =CH(CH 2 ) n CH 3 CH 3 (CH 2 ) n CH=CH(CH 2 ) n CH 3 + CH 2 =CH 2 The primary reaction products include ethylene and a longchain alkene with symmetrical internal placement of the double bond. Synthetic fuel processing plants produce large volumes of linear and branched terminal alkenes within the C 4 -C 8 range.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Metathesis of 1‐Hexene over Heterogeneous Tungsten‐Based Catalysts

2015

View full text Add to dashboard Cite

1-Hexene metathesis was performed over standard and potassium-doped WO 3 /SiO 2 catalysts. The samples were tested at various reaction temperatures, molar feed compositions, and space times. Under the applied reaction conditions, doping with potassium reduced the isomerization and cracking activity of the catalyst by at least half and improved the yield of detergent-range alkenes twofold. However, increasing the potassium loading to a higher amount resulted in a significant reduction in the metathesis activity as both Brønsted and Lewis acid sites were affected. Optimum operating conditions for the yield of detergent-range alkenes were identified using response surface methodology.

show abstract

Break-in Behavior of a Tungsten Oxide on Silica Catalyst in Propylene Disproportionation

Cited by 14 publications

References 3 publications

Enhanced metathesis of ethylene and 2-butene on tungsten incorporated ordered mesoporous silicates

Enhanced metathesis of ethylene and 2-butene on tungsten incorporated ordered mesoporous silicates

Effect of pretreatment atmosphere of WO_x/SiO₂catalysts on metathesis of ethylene and 2-butene to propylene

Metathesis of 1‐Hexene over Heterogeneous Tungsten‐Based Catalysts

Contact Info

Product

Resources

About

Break-in Behavior of a Tungsten Oxide on Silica Catalyst in Propylene Disproportionation

Cited by 14 publications

References 3 publications

Enhanced metathesis of ethylene and 2-butene on tungsten incorporated ordered mesoporous silicates

Enhanced metathesis of ethylene and 2-butene on tungsten incorporated ordered mesoporous silicates

Effect of pretreatment atmosphere of WOx/SiO2catalysts on metathesis of ethylene and 2-butene to propylene

Metathesis of 1‐Hexene over Heterogeneous Tungsten‐Based Catalysts

Contact Info

Product

Resources

About

Effect of pretreatment atmosphere of WO_x/SiO₂catalysts on metathesis of ethylene and 2-butene to propylene