Isomerization of n-Heptane over Pd-Loaded Silico-Alumino-Phosphate Molecular Sieves

Parlitz, B.; Schreier, E.; Zubowa, Heide-Lore; Eckelt, Reinhard; Lieske, E.; Lischke, G.; Fricke, R.

doi:10.1006/jcat.1995.1182

Cited by 109 publications

(46 citation statements)

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“…A quite similarly result was obtained when Al metal was substituted with equimolar concentrations of Zn and Cd. The chemical interpretation to this is that that the metal species (Al, Zn or Cd) when incorporated simultaneously with the Pt species, are merely deposited (chemisorbed) onto the zeolite (oxidic) surface next to the Pt sites but not that Pt and Al species can undergo competitive or selective adsorption on the zeolite surface reported in some literatures (Weitkamp et al, 1983;Taylor & Petty, 1994;Parlitz et al, 1995;Lugstein et al, 1999). However, the incorporation does not contribute to the variation of the density of the surface acid sites.…”

Section: Galadima Et Al (Swj):15-22mentioning

confidence: 99%

Solid acid catalysts in heterogeneous n-alkanes hydroisomerisation for increasing octane number of gasoline

Galadima¹,

Anderson²,

Wells³

2010

Science World Journal

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As the current global environmental concerns have prompted regulations to reduce the level of aromatic compounds, particularly benzene and its derivatives in gasoline, hydroisomerisation of n-alkanes is becoming a major alternative for enhancing octane number. Series of solid acid catalysts comprising of Freidel crafts, zirconias, MoO3-based (MOB), chlorinated Al2O3, heteropoly acids and bifunctional zeolite based catalysts have been tested in this respect. This paper reviewed important studies conducted on these catalysts with the aim of identifying areas requiring further investigation(s). Freidel craft catalysts are currently abandoned due to corrosion and disposal problems. MOB and heteropoly acids have good resistance to nitrogen and sulphur in a reaction stream but have poor thermal stability, difficult to regenerate and with mechanism their action only partly resolved. Bifunctional zeolites on the other hand are increasingly becoming promising catalysts due to resulting high acidity, activity and easy regeneration properties. Both solid and gaseous acid modifiers could similarly modify their textural characteristics. The activities of all catalysts could under uncontrolled conditions lead to side reactions such as cracking, aromatisation and dehydrogenation.

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Section: Galadima Et Al (Swj):15-22mentioning

confidence: 99%

Solid acid catalysts in heterogeneous n-alkanes hydroisomerisation for increasing octane number of gasoline

Galadima¹,

Anderson²,

Wells³

2010

Science World Journal

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“…However, since the amount of Pt was so small, the Pt sites were not rich enough to allow the overall reaction to proceed smoothly. It was after the Pt content has exceeded a certain value that the catalyst could exhibit the best performance, and this was because the catalyst had established a proper balance between the acid and (6) 0.108 0.38 Pt/MgAPO-11 (9) 0.094 0.33 the dehydrogenation/hydrogenation functions [14]. For the MgAPO-11(3) catalyst, it can be seen that 0.5 wt.% Pt was the optimum metal content for the hydroisomerization of n-dodecane.…”

Section: Interaction Between Pt and The Molecular Sievesmentioning

confidence: 99%

“…The second reduction peak of Pt/MgAPO-11(3), Pt/MgAPO-11 (6) and Pt/MgAPO-11 (9) were centered at 403, 440 and 448°C, respectively. The results indicated that the interaction between the Pt species and the MgAPO-11 became stronger with the increase of the Mg content.…”

Section: Interaction Between Pt and The Molecular Sievesmentioning

confidence: 99%

“…Generally, isomerization reactions are carried out over bifunctional catalysts containing metallic sites for dehydrogenation/hydrogenation, and acidic sites for skeletal isomerization via carbenium ions [4][5][6]. In recent years, bifunctional catalysts based on SAPO-11 have been developed for the hydroisomerization of n-alkanes [7][8][9][10][11][12][13][14][15]. The catalysts exhibit excellent catalytic properties due to the special pore structure (one-dimensional channel system with 10-membered ring openings of 0.39 nm Â 0.63 nm pore diameter) and the moderate acidity of the SAPO-11 support.…”

Section: Introductionmentioning

confidence: 99%

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Performance of Pt/MgAPO-11 Catalysts in the Hydroisomerization of n-dodecane

Yang

Tian

et al. 2006

Catal Lett

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MgAPO-11 molecular sieves with varying Mg contents synthesized by the hydrothermal method were used as supports for bifunctional Pt/MgAPO-11 catalysts. MgAPO-11 molecular sieves and the corresponding catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), temperature-programmed desorption of NH 3 (NH 3 -TPD), differential thermogravimetric (DTG) analysis, temperature-programmed reduction of H 2 (H 2 -TPR), H 2 chemisorption and catalytic reaction evaluation. The results indicated that the acidity generated via the substitution of Mg 2+ for Al 3+ in the framework increased with the Mg content. Acting as acidic components, the MgAPO-11 molecular sieves loaded with Pt were tested in the hydroisomerization of n-dodecane. Optimum isomer yield was obtained over the Pt/MgAPO-11 catalyst that had neither the highest acidity nor the highest Pt loading among the tested catalysts. In fact, the activity and the isomer yield both could attain a maximum on 0.5 wt.% Pt/MgAPO-11 catalysts with differing Mg contents. A lower Mg content resulted in an insufficient acidity, whilst a higher Mg content weakened the dehydrogenation/hydrogenation function of the Pt. These inappropriate balances between the acidic and the metallic functions of the catalysts would lead to low activities and isomer yields. On the other hand, the 0.5 wt.% Pt/MgAPO-11(3) catalyst was found to have a good balance between the acidic and the metallic functions, and thus exhibited both high activity and isomer yield in comparison with the conventional 0.5 wt.% Pt/SAPO-11 catalyst.

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“…[4] Pt/Cl/alumina is the preferred catalyst for commercial C5/C6 isomerization. Pt/mordent catalysts are also used [5], n-C7 isomerization over Pt or Pd on mordent [6] , ZSM-5 [6], β-zeolite [7][8], Y zeolite [9][10], SAPO [11][12][13], SO4 2-/ZrO2 [14][15], and WOx-ZrO2 [16] has been reported. Several patents covering isomerization of paraffin's including C7 over catalysts based on amorphous alumina and silica-alumina supports have been granted [17].…”

Section: Introductionmentioning

confidence: 99%

Effect of SiO₂/Al₂O₃Ratio on Micro-Mesopore Formation for Pt/Beta-MCM-41 via NaOH Treatment and the Catalytic Performance in N-heptane Hydro isomerization

Gao

Shi²,

Liu

et al. 2018

IOP Conf. Ser.: Earth Environ. Sci.

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Abstract. Micro-mesoporous composite material Beta-MCM-41(BM) were hydrothermally synthesized by treating parent beta with molar SiO 2 /Al 2 O 3 ratios of 12.5, 20 and 30 as precursors. The influence of SiO 2 /Al 2 O 3 ratio of zeolite beta on effective micro-mesoporous composite formation was studied by investigating the crystallinity, morphology, chemical composition, acidity and textural property of Beta-MCM-41 through XRD, nitrogen adsorption, SEM, TEM, NH 3 -TPD, FTIR and Pyridine-FTIR. The catalytic performance was evaluated in terms of n-heptane hydro isomerization. The results demonstrated that Beta-MCM-41 supported Pt catalysts showed higher selectivity to isoheptanes than Pt/Beta. It was attributed to the superiorities of the pore structure and mesoporous accelerated the diffusion of larger molecules of isoheptanes.

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Isomerization of n-Heptane over Pd-Loaded Silico-Alumino-Phosphate Molecular Sieves

Cited by 109 publications

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Solid acid catalysts in heterogeneous n-alkanes hydroisomerisation for increasing octane number of gasoline

Solid acid catalysts in heterogeneous n-alkanes hydroisomerisation for increasing octane number of gasoline

Performance of Pt/MgAPO-11 Catalysts in the Hydroisomerization of n-dodecane

Effect of SiO₂/Al₂O₃Ratio on Micro-Mesopore Formation for Pt/Beta-MCM-41 via NaOH Treatment and the Catalytic Performance in N-heptane Hydro isomerization

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Isomerization of n-Heptane over Pd-Loaded Silico-Alumino-Phosphate Molecular Sieves

Cited by 109 publications

References 0 publications

Solid acid catalysts in heterogeneous n-alkanes hydroisomerisation for increasing octane number of gasoline

Solid acid catalysts in heterogeneous n-alkanes hydroisomerisation for increasing octane number of gasoline

Performance of Pt/MgAPO-11 Catalysts in the Hydroisomerization of n-dodecane

Effect of SiO2/Al2O3Ratio on Micro-Mesopore Formation for Pt/Beta-MCM-41 via NaOH Treatment and the Catalytic Performance in N-heptane Hydro isomerization

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Effect of SiO₂/Al₂O₃Ratio on Micro-Mesopore Formation for Pt/Beta-MCM-41 via NaOH Treatment and the Catalytic Performance in N-heptane Hydro isomerization