Skeletal Isomerization of n-Butane Catalyzed by an Acidic Cesium Salt of 12-Tungstophosphoric Acid

Na, Kyutae; Okuhara, Toshio; Misono, Makoto

doi:10.1246/cl.1993.1141

Cited by 40 publications

(18 citation statements)

References 9 publications

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“…The surface acidities of Cs 2.5 H 0.5 W and H 3 W were 43 and 17 µmol g −1 , respectively. Koyano et al (13) and Na et al (14) reported that the surface acidity of Cs x H 3-x W initially decreased from x = 0 to 2, where at x = 0 and x = 2, the surface acidity was 14 and 0.4 µmol g −1 , respectively. When H + was substituted by Cs + , at x = 2.5, the surface acidity was 60 µmol g −1 before dropping to zero at x = 3 (13).…”

Section: Resultsmentioning

confidence: 99%

Hydrolysis of palm olein catalyzed by solid heteropolyacids

Yow

Liew

2002

J Americ Oil Chem Soc

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The hydrolysis activity of superacids on palm olein, including tungstophosphoric acid and molybdophosphoric acid and their partially ion-exchanged cesium (Cs) salt, were investigated and compared with macroporous cation-exchanged resin and aluminum-incorporated mesoporous molecular sieve. The activities of the superacids supported on the resin and silica were also determined. The reactions were carried out in a stirred batch reactor with continuous steam injection at temperatures from 140 to 180°C. The reaction kinetics, obtained by regression, are first order with respect to TG of the superacids and Cs salts. Of the catalysts studied, the superacids loaded onto cation-exchanged resins were the most active on a weight basis. However, in terms of the turnover number per acid site, the Cs salt of tungstophosphoric acid had 13 times the activity of the cation-exchanged resin. The original superacids had lower activities than the Cs salts in terms of their turnover number. The observations are qualitatively in line with the higher acid strengths of the catalysts, as confirmed by the low activity of the aluminum silicate mesoporous molecular sieve, which is known to have a high concentration of low-to moderate-strength acid sites. The activation energy of the reaction with the Cs salts was ~49 kJ mol −1 . This is rather low as compared to that catalyzed by the cation-exchanged resin.

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Section: Resultsmentioning

confidence: 99%

Hydrolysis of palm olein catalyzed by solid heteropolyacids

Yow

Liew

2002

J Americ Oil Chem Soc

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“…[29][30][31] From the synthetic point of view, the typical procedure for preparation of cesium salts of HPAs are generally proceeded through a solution method by titrating the controlled amount of an aqueous solution of Cs 2 CO 3 into the aqueous solution of HPA. [32,33] In the previous report we found that the solid synthesis method by ball milling of HPA with CsNO 3 at room temperature is much simpler than the solution method, which is convenient to control the cesium content and has great potential in large scale preparation. [34] In the present work, cesium salts of vanadium-substituted molybdophosphoric acid, Cs x H 3 ＋ n -x PMo 12 -n V n O 40 (n＝0, 1, 2, x＝0.5-3.0), have been prepared by the solid synthesis method.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Hydroxylation of Benzene to Phenol with Hydrogen Peroxide over Cesium Salts of Keggin-type Heteropoly Acids

Shi¹,

Li²,

Yuanhang³

et al. 2012

Acta Chim. Sinica

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“…Suzuki et al [13] observed that Pd x H 3-2x PW 12 O 40 /SiO 2 catalyzed n-hexane isomerization in the presence of hydrogen. Na et al [14,15] found that an acidic Cs salt of H 3 PW 12 O 40 , namely Cs 2.5 H 0.5 PW 12 O 40 , was very active and selective for the n-butane skeletal isomerization. Besides the application of heteropoly acid salts, heteropoly acids (HPAs), in particular those with Keggin structure H 8-x [X x+ M 12 O 40 ] (X = P 5+ or Si 4+ , M = W 6+ or Mo 6+ ), which are strong brønsted acids were also extensively used as acid catalysts [16].…”

Section: Introductionmentioning

confidence: 99%

A Highly Effective Pt and H3PW12O40 Modified Zirconium Oxide Metal–Acid Bifunctional Catalyst for Skeletal Isomerization: Preparation, Characterization and Catalytic Behavior Study

Zhang

et al. 2008

Catal Lett

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A series of metal-acid bifunctional catalysts with varying quantities of platinum and tungstophosphoric acid (TPA) supported on zirconium oxide were prepared by co-impregnation method. In skeletal isomerization of n-pentane using catalyst with 1% Pt and 30% TPA loadings the conversion of the reactant which was close to the equilibrium conversion reached ca. 65% and the selectivity towards the product was as high as ca. 97% at atmospheric pressure and relatively low reaction temperature (200°C). The phase structure, chemical structure, surface physicochemical properties, surface element oxidation states and hydrogen reduction behavior of the catalysts were wellcharacterized via XRD, FT-IR, N 2 adsorption-desorption determination (BET), XPS and TPR. The effects of Pt and TPA loadings, calcination temperature, reaction temperature and weight hourly space velocity (WHSV) on the catalytic performance were investigated. In addition, a long period catalytic stability test of the catalyst with optimal Pt and TPA loadings was carried out, which indicated that the bifunctional catalyst was in possession of good stability in skeletal isomerization along with high catalytic activity under the experimental conditions.

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Skeletal Isomerization of n-Butane Catalyzed by an Acidic Cesium Salt of 12-Tungstophosphoric Acid

Abstract: A salt of H3PW12O40, Cs2.5H0.5PW12O40, catalyzed efficiently the skeletal isomerization of n-butane to isobutane at 300 °C. The activity and selectivity were much higher than those of SO22−/ZrO2. H-ZSM-5 was more active than Cs2.5H0.5PW12O40, but the selectivity was very low.

Cited by 40 publications

References 9 publications

Hydrolysis of palm olein catalyzed by solid heteropolyacids

Hydrolysis of palm olein catalyzed by solid heteropolyacids

Catalytic Hydroxylation of Benzene to Phenol with Hydrogen Peroxide over Cesium Salts of Keggin-type Heteropoly Acids

A Highly Effective Pt and H3PW12O40 Modified Zirconium Oxide Metal–Acid Bifunctional Catalyst for Skeletal Isomerization: Preparation, Characterization and Catalytic Behavior Study

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