Studies of sulphated mixed oxides (ZrO2–SO4–La2O3) in the isomerization of n-hexane

Silva–Rodrigo, R.; Cruz-Domínguez, E.L.; Angel, F.E. Lugo-del; Navarrete‐Bolaños, Juan; García-Alamilla, Ricardo; Olivas, A.; Melo-Banda, J.A.; Cruz-Netro, L.C.; Zamora-Ramírez, G.; Castillo-Mares, A.

doi:10.1016/j.cattod.2014.10.013

Cited by 23 publications

(18 citation statements)

References 22 publications

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“…Latterly, nickel and/or lanthanum have been used to improve the reactivity of SZ catalysts for n ‐butane, n ‐pentane, and n ‐hexane isomerization . The nickel, palladium, and platinum belong to one family, so many attempts were made on nickel‐modified SZ to replace the noble metal.…”

Section: Strategies For Improving N‐alkane Isomerization Activity Ovementioning

confidence: 99%

“…Latterly, nickel and/or lanthanum have been used to improve the reactivity of SZ catalysts for n-butane, 124,136 n-pentane, 114,[149][150][151] and n-hexane isomerization. 118,152,153 The nickel, palladium, and platinum belong to one family, so many attempts were made on nickel-modified SZ to replace the noble metal. When the impregnation method is employed to introduce nickel on SZ surface, different precursors result in different modification effects.…”

Section: Ni and La Promotionmentioning

confidence: 99%

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Alkane isomerization over sulfated zirconia solid acid system

et al. 2020

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Summary Sulfated zirconia (SZ) and its modified versions attract great interest in recent years, because of their promising potential in n‐alkane isomerization. The oxidative and protonation routes are active and interactional in n‐alkane activation over SZ catalysts. The bimolecular reaction becomes dominant with increasing the density of active sites on SZ surface and decreasing the carbon chain of feed. Pentane and hexane are mainly isomerized by protonated cyclopropane mechanism, while which is thermodynamically unflavored for n‐butane isomerization. The deactivation of SZ catalysts is primarily caused by the loss of superacidity and oxidizing ability, resulted from the structure changes of sulfate species. Several strategies for improving the activity of SZ are reviewed. The intrinsic structure‐reactivity relationship of SZ catalysts in alkane isomerization is updated to illuminate the prerequisite for the highly active catalysts and the mechanism of active sites formation. The applications of Pt/SZ in fixed‐bed and unmodified SZ in circulating fluidizing bed in light alkanes isomerization are compared with the conventional technologies based on the chlorinated alumina catalysts. Finally, the future study of SZ catalysts is outlooked from the academic investigations to the industrial applications.

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Section: Strategies For Improving N‐alkane Isomerization Activity Ovementioning

confidence: 99%

Section: Ni and La Promotionmentioning

confidence: 99%

Alkane isomerization over sulfated zirconia solid acid system

et al. 2020

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“…In this sense, isomerization of light para n using solid acid catalysts, as a key technology in the production of clean fuels, has been raised [2][3][4][5]. These reactions are limited by thermo-dynamic equilibrium, favoring low temperatures [6,7]. Many recent e orts are focused on improving and development of this process.…”

Section: Introductionmentioning

confidence: 99%

“…have been widely studied in alkane isomerization [4,5,[8][9][10]. Studies on the employed catalysts for this reaction showed that Sulfated Zirconia (SZ), as an environmentally friendly catalyst, was believed to be the most promising catalyst among the solid acids due to low-temperature hydrocarbon skeletal rearrangements for thermodynamic consideration [6,7,[10][11][12].…”

Section: Introductionmentioning

confidence: 99%

n-pentane isomerization over Pt-Al promoted sulfated zirconia nanocatalyst

et al. 2017

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Abstract. Platinum containing sulfated zirconia (Pt-SZ/Al) catalyst was prepared by precipitation method. Characterization of the prepared catalyst was performed using XRD and SEM, and catalytic activity was studied for isomerization of nC 5 at atmospheric conditions and temperatures of 180-240 C in a ow reactor. The e ects of reaction temperature, H 2 /nC 5 ratio, and WHSV were investigated. As revealed by SEM and XRD, the prepared sulfated zirconia was of nanoscale size and had predominantly tetragonal crystalline phase. n-pentane conversion increased with increasing temperature and selectivity decreased. The optimal reaction temperature was 220 C where n-pentane conversion and isopentane selectivity were 70% and 94%, respectively. The positive e ect of H 2 /nC 5 ratio was observed on nC 5 conversion and iC 5 selectivity in the investigated H 2 /nC 5 ratio range. This trend of variation was related to the role of acid and metallic sites on the reaction pathway. As expected, increase in the WHSV, which reduces contact time between reactant and catalyst, decreased nC 5 conversion and increased selectivity toward iC5. The RON of the product increased with increasing temperature; then, it showed slight decrease at higher temperature. The decrease in the activation energy was observed, which can be attributed to the di erent reaction mechanisms or di erent rate-determining steps.

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“…sulfated zirconia lattice generate materials with enhanced catalytic activity and selectivity [19][20][21] .…”

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confidence: 99%

Catalytic application of SO₄²⁻/Fe–ZrO₂nanoparticles synthesized by a urea hydrolysis method for environmentally benign one pot synthesis of 1,8-dioxodecahydroacridines

Pradhan

Mishra

2015

RSC Adv.

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A series of Fe 2 O 3 -ZrO 2 mixed oxides (FexZr) were prepared by colloidal precipitation method using urea as mild hydrolyzing agent. The sulfate ions were grafted onto the surface of the mixed oxide by treatment with dilute sulfuric acid and subsequent thermal activation. The resulting sulfated grafted mixed oxides (SFexZr) were characterized using XRD, FTIR, Raman, surface area measurement, UV-Vis, XPS, TPD, FESEM and HRTEM techniques. XRD study indicated formation of a substitutional type solid solution in a limited composition range due to incorporation of iron ions into the zirconia lattice. The selective stabilization of the tetragonal phase of zirconia was observed in the mixed oxide system. The microstructural properties of the sulfate grafted mixed oxide were obtained from the Fourier analysis of the broadened XRD profiles. The presence of well dispersed iron oxide species in the zirconia lattice was ascertained from the Raman and UV-Vis study. XPS and FTIR study confirmed the presence of grafted sulfate functional groups. HRTEM analysis of the SFe10Zr sample revealed the presence of well dispersed mixed oxide particles with size in the range of 10-30 nm. The catalytic activity of the SFexZr material was evaluated for the synthesis of 1,8-dioxo-decahydroacridines by multicomponent condensation of dimedone, substituted aryl aldehyde and substituted anilines. A variety of dioxodecahydroacridines molecules were obtained with high yield and purity. The SFe10Zr material exhibited high surface area, enhanced sulfur retention and excellent catalytic activity for synthesis of the 1,8-dioxo-decahydroacridines molecules.

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Studies of sulphated mixed oxides (ZrO2–SO4–La2O3) in the isomerization of n-hexane

Cited by 23 publications

References 22 publications

Alkane isomerization over sulfated zirconia solid acid system

Alkane isomerization over sulfated zirconia solid acid system

n-pentane isomerization over Pt-Al promoted sulfated zirconia nanocatalyst

Catalytic application of SO₄²⁻/Fe–ZrO₂nanoparticles synthesized by a urea hydrolysis method for environmentally benign one pot synthesis of 1,8-dioxodecahydroacridines

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Studies of sulphated mixed oxides (ZrO2–SO4–La2O3) in the isomerization of n-hexane

Cited by 23 publications

References 22 publications

Alkane isomerization over sulfated zirconia solid acid system

Alkane isomerization over sulfated zirconia solid acid system

n-pentane isomerization over Pt-Al promoted sulfated zirconia nanocatalyst

Catalytic application of SO42−/Fe–ZrO2nanoparticles synthesized by a urea hydrolysis method for environmentally benign one pot synthesis of 1,8-dioxodecahydroacridines

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Catalytic application of SO₄²⁻/Fe–ZrO₂nanoparticles synthesized by a urea hydrolysis method for environmentally benign one pot synthesis of 1,8-dioxodecahydroacridines