Synthesis and Characterization of Chromium-Added Pt/Beta Zeolite and its Catalytic Performance for n-Heptane Isomerization

Izutsu, Yoshiyuki; Oku, Yuki; Hidaka, Yusuke; Yoshida, Kaname; Sasaki, Yukichi; Sekine, Yasushi; Kikuchi, Eiichi; Matsukata, Masahiko

doi:10.1007/s10562-013-0973-y

Cited by 15 publications

(17 citation statements)

References 27 publications

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“…Nowadays, the hydroisomerization of straight-chain paraffins is very important in the oil refining industry, especially in enhancing the gasoline octane number, improving the low-temperature performance of diesel, as well as in the production of lube oils with high viscosity index [1,2]. Although hydroisomerization of C4-C6 fractions is well established [3,4], there is a need for an efficient catalyst for hydroisomerization of alkanes with longer chains (C7-C8 fractions and even higher). Weitkamp and co-workers have made pioneer effort in understanding the effect of the alkane chain length on the hydroisomerization & hydrocracking reactions over various catalysts [5,6].…”

Section: Introductionmentioning

confidence: 99%

Beta-MCM-41 micro-mesoporous catalysts in the hydroisomerization of n-heptane: Definition of an indexed isomerization factor as a performance descriptor

Gao

Shi

Etim

et al. 2019

Microporous and Mesoporous Materials

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Beta-MCM-41(BM) composites consisting of Beta zeolite grown on MCM-41 type mesoporous structure were prepared. The composite materials were used as a support for stabilization of Pt. The Pt containing catalysts (Pt/HBM) were applied in nheptane hydroisomerization reaction. The Pt/HBM catalysts showed higher n-heptane conversion and higher selectivity to isoheptanes in comparison to pure Beta and MCM-41. The results were explained by the accelerated diffusion of isoheptanes in the Pt/HBM composites, and the high concentration of acid sites with a moderate strength in the composites, which reduced the cracking of reactants and products. Based on the experimental results, an indexed isomerization factor (IIF) was deduced, which is correlated with the physical properties of the supports. The results indicated that the isoheptane yield of the catalysts is strongly dependent on the support (IIF). The general IIF descriptor for predicting the isomerization performance of support materials can provide precise guidance for the design of new micro-mesoporous composites.

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Section: Introductionmentioning

confidence: 99%

Beta-MCM-41 micro-mesoporous catalysts in the hydroisomerization of n-heptane: Definition of an indexed isomerization factor as a performance descriptor

Gao

Shi

Etim

et al. 2019

Microporous and Mesoporous Materials

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“…We recently reported that platinum and chromium loaded zeolites were useful as catalysts for the skeletal isomerization of n-heptane, and these elements were highly and uniformly dispersed in the micropores of zeolite beta. 10 While Liu et al 29 similarly reported the positive effect of Cr addition on Pt/ dealuminated Hβ for n-heptane isomerization, the mechanism of change of platinum dispersion and the effect of Pt dispersion on products selectivity are open questions. In this study, the physicochemical structure and states of platinum and chromium in PtCr/beta were investigated with a variety of analytical techniques and molecular dynamics (MD) simulation.…”

Section: ■ Introductionmentioning

confidence: 99%

Physicochemical Characterization of Highly Dispersed Platinum and Chromium on Zeolite Beta

et al. 2014

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Structures of platinum and chromium supported on zeolite beta were investigated by XAFS, XPS, UV–vis, NH3-TPD, XRD, CO chemisorption, and molecular dynamics simulation. Both platinum and chromium were uniformly dispersed in the micropore of zeolite beta. Loading of chromium helped platinum to disperse highly and stabilized in the micropore of beta. Major species of platinum on PtCr/beta after calcination at 773 K was Pt2+ forming a Pt–O bond. The Pt–O bond disappeared, and a Pt–Pt bond did not appear by reducing PtCr/beta in hydrogen, accompanying formation of Pt0. Chromium was loaded as chromate anion in the micropore of zeolite. Results of molecular dynamics simulation showed that Pt2+ associated with CrO4 2– in the micropore of zeolite beta was more stable than those in the absence of chromium species. We concluded that CrO4 2– electrostatically stabilizes Pt2+ and inhibits migration and aggregation of platinum.

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“…Zeolite catalyst samples have been synthesized on the basis of NaM zeolite (SiO 2 /Al 2 O 3 = 9.8, produced by JS "Sorbent", Nizhnij Novgorog, Russia). H-form zeolite (HM) has been obtained by threefold ion exchange of native sodium cations for NH 4 + from ammonium nitrate NH 4 NO 3 aqueous solution (3 mol/l). Ion-exchange duration was performed at 358 K for 3 h, followed by calcination in air (823 K, 2 h).…”

Section: Methodsmentioning

confidence: 99%

“…The isomerization of n-alkanes is a process of great importance for the oil refining industry. This reaction transforms linear alkanes into branched ones, which have higher octane numbers and therefore utilize light gasoline fraction of atmosphere refining [1][2][3][4][5][6]. Usually, branched paraffins are obtained by isomerization over bifunctional catalysts, which have Broensted and Lewis acidic and hydrogenating-dehydrogenating active sites [7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

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n-Hexane Isomerization Over Nickel-Containing Mordenite Zeolite

Patrylak¹,

Krylova²,

Pertko³

et al. 2020

Ch&Cht

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Synthesis and Characterization of Chromium-Added Pt/Beta Zeolite and its Catalytic Performance for n-Heptane Isomerization

Cited by 15 publications

References 27 publications

Beta-MCM-41 micro-mesoporous catalysts in the hydroisomerization of n-heptane: Definition of an indexed isomerization factor as a performance descriptor

Beta-MCM-41 micro-mesoporous catalysts in the hydroisomerization of n-heptane: Definition of an indexed isomerization factor as a performance descriptor

Physicochemical Characterization of Highly Dispersed Platinum and Chromium on Zeolite Beta

n-Hexane Isomerization Over Nickel-Containing Mordenite Zeolite

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