Skeletal isomerization of 1-butene on ZrO2/Al2O3 treated with sulfate ion

Luy, J.C.; Yori, Juan Carlos; Castro, Alberto A.; Parera, J.M.

doi:10.1007/bf02063818

Cited by 14 publications

(6 citation statements)

References 12 publications

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“…Titania-silica system is considered a potential candidate as photocatalyst [4][5][6][7][8][9]. Further, the catalytic activity and anatase-phase stability are closely related [10], and silica addition has been reported in general to shift the anatase-rutile transformation to higher temperature range [11]. However, no detailed study has been reported on the effect of synthesis conditions on characteristics of the composite powder with particular reference to specific surface area as well as anatase-rutile transformation temperature.…”

Section: Introductionmentioning

confidence: 99%

Photodegradation of toluene using silica-embedded titania

Zhang

2005

Journal of Non-Crystalline Solids

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Section: Introductionmentioning

confidence: 99%

Photodegradation of toluene using silica-embedded titania

Zhang

2005

Journal of Non-Crystalline Solids

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“…The starting point was to use porous, high surface area silica or alumina as a skeleton material and to grow the desired surface oxide phase on this material by the atomic layer epitaxy (ALE) technique with the use of sequential reactions of ZrCl 4 and H 2 O vapors. Earlier work aimed at dispersing ZrO 2 on silica or alumina supports has concentrated on deposition from the liquid phase using zirconyl chloride or nitrate, − zirconium nitrate, zirconium ethoxide , or zirconium tert -butoxide 7 as precursor.…”

Section: Introductionmentioning

confidence: 99%

Controlled Formation of ZrO₂ in the Reaction of ZrCl₄ Vapor with Porous Silica and γ-Alumina Surfaces

1996

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The reaction of ZrCl4 vapor at 300, 450, and 600 °C with silica and γ-alumina preheated at 300 and 600 °C was studied by XRD, FTIR, 1H MAS NMR, and chemical etching with sulfuric acid. NMR and FTIR revealed a consumption of OH groups in the reaction. However, subsequent water vapor treatment brought some of the OH groups of the support back, indicating that part of the surface had been directly chlorinated. The ratio between permanently consumed OH groups and directly chlorinated OH groups depended on the reaction temperature. OH groups were permanently consumed in mono- and bimolecular reactions of ZrCl4, leading to the formation of isolated M−O−ZrCl3 and (M−O)2−ZrCl2 species (M = Al or Si), respectively. Direct chlorination was associated with the formation of crystalline ZrO2 agglomerates, as detected by XRD in the samples prepared at 450 and 600 °C. These agglomerates were insoluble in sulfuric acid. Although at the reaction temperature of 300 °C the samples were amorphous in XRD, the reappearance of some OH groups on the original surface after water treatment, together with etching tests, suggested that agglomerates were also formed at that temperature. In addition to agglomeration and exchange reactions with OH groups, on 600 °C alumina ZrCl4 dissociated to (Al−O) pairs. This led to a higher Zr saturation density and Cl/Zr ratio on alumina than on silica. The reactions of the HCl evolved in the main reactions were considered minor. Increasing the preheat and reaction temperatures decreased the Zr concentration on the surface and thus diminished the surface coverage. The surfaces of the ZrCl4-modified and water-treated silica and alumina surfaces consisted of Zr−OH groups formed in the hydrolysis of isolated ZrCl x species, original OH groups of the supports, and ZrO2 agglomerates formed in the vicinity of siloxanes and (Al−O) pairs.

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“…3. The skeletal isomerization of 1-butene to isobutene proceeds only when the catalyst has a strong acidity such as superacid-like activity [26]. The skeletal isomerization was observed even at 200°C and its selectivity to isobutene was 4.6 %.…”

Section: Resultsmentioning

confidence: 98%

Polymer synthesis by solid-acid catalyst based on heteropolyacid ammonium salt

et al. 2015

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Ring-opening polymerizations of four kinds of monomers such as glycidyl phenyl ether, oxetane (OX), e-caprolactone (CL), and 2,2-dimethyltrimethylene carbonate were performed with a silica-supported catalyst based on heteropolyacid ammonium salt, (NH 4 ) 3 PW 12 O 40 /SiO 2 . Preparation of the catalyst was done by an impregnation of (NH 4 ) 3 PW 12 O 40 onto SiO 2 in aqueous ammonia, followed by its calcination. Selectivities for skeletal isomerizations of 1-butene exhibited a strong acidity of the (NH 4 ) 3 PW 12 O 40 /SiO 2 . Among four monomers, the OX and CL were the promising monomers for this polymerization system. The resulting poly(OX) and poly(CL) with number-average molecular weight (M n ) of 2900-6500 and 5500-8600 were obtained in 65-80 and 93-96 % yields, respectively. Furthermore, copolymerization of OX and CL successfully proceeded, affording poly(OX-co-CL) with compositions of OX:CL = 63:37, 50:50, and 37:63 having M n = 2400-3800 in 64-84 % yields.

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Skeletal isomerization of 1-butene on ZrO2/Al2O3 treated with sulfate ion

Cited by 14 publications

References 12 publications

Photodegradation of toluene using silica-embedded titania

Photodegradation of toluene using silica-embedded titania

Controlled Formation of ZrO₂ in the Reaction of ZrCl₄ Vapor with Porous Silica and γ-Alumina Surfaces

Polymer synthesis by solid-acid catalyst based on heteropolyacid ammonium salt

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Skeletal isomerization of 1-butene on ZrO2/Al2O3 treated with sulfate ion

Cited by 14 publications

References 12 publications

Photodegradation of toluene using silica-embedded titania

Photodegradation of toluene using silica-embedded titania

Controlled Formation of ZrO2 in the Reaction of ZrCl4 Vapor with Porous Silica and γ-Alumina Surfaces

Polymer synthesis by solid-acid catalyst based on heteropolyacid ammonium salt

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Product

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Controlled Formation of ZrO₂ in the Reaction of ZrCl₄ Vapor with Porous Silica and γ-Alumina Surfaces