Alkylation of Isobutane with Butenes Catalyzed by a Cesium Hydrogen Salt of 12-Tungstophosphoric Acid

Okuhara, Toshio; Yamashita, Masayuki; Na, Kyutae; Misono, Makoto

doi:10.1246/cl.1994.1451

Cited by 70 publications

(19 citation statements)

References 6 publications

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“…9,10. An aqueous solution of Cs 2 CO 3 was added dropwise to that of H 3 PW 12 O 40 , and the obtained precipitate was evaporated at 318 K followed by aging overnight.…”

Section: Methodsmentioning

confidence: 99%

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Self-Humidifying Cs2.5H0.5PW12O40 / Nafion / PTFE Composite Membrane for Proton Exchange Membrane Fuel Cells

Ming-qiang

Shao

Zhang

et al. 2006

Electrochemical and Solid-State Letters

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A Cs 2.5 H 0.5 PW 12 O 40 /Nafion/polytetrafluoroethylene ͑PTFE͒ self-humidifying composite membrane was developed for proton exchange membrane fuel cells. It was prepared by recasting the Cs 2.5 H 0.5 PW 12 O 40 /Nafion self-humidifying layer onto the two sides of a Nafion/PTFE composite membrane with a solution-recast method. Due to the strong acidic, hydrophilic, and redox properties of Cs 2.5 H 0.5 PW 12 O 40 , the Cs 2.5 H 0.5 PW 12 O 40 /Nafion self-humidifying layer not only contributes to humidify the membrane but also contributes to the improvement of the open-circuit voltage of the fuel cell. When the self-humidifying composite membrane was employed as an electrolyte in H 2 /O 2 PEMFC, a higher maximum power density value ͑1.1 W/cm 2 ͒ was obtained than that of Nafion/PTFE composite membrane ͑0.6 W/cm 2 ͒, under the operating conditions of 70°C and at the humidified temperature of 20°C.The proton exchange membrane fuel cell ͑PEMFC͒ attracts much attention due to its high efficiency, high power density, zero emission, and low-temperature start-up as a power sources suitable for both stationary and mobile application. However, the typical membrane currently used for the PEMFC, such as Dupont's Nafion or perfluorosulfonic acid ͑PFSA͒ membrane, shows a significant loss in conductivity at a lower relative humidity ͑RH͒ environment. 1 Thus the reaction gas needs to be humidified in the PEMFC. But the humidifier will make the whole system complex and large. Therefore these needs promote the research and development selfhumidifying membrane. 2 Up to now, many materials such as Pt, 3 metal oxides, 4 heteropoly acid, 5 and ZrHPO 4 6 have been used to highly disperse in the Nafion or sulfonated poly ͑ether ether ketone͒ ͑SPEEK͒ resin to fabricate self-humidifying membrane. However, due to the poor mechanical strength and stability of those selfhumidifying membranes, the humidifier still has to be used in the PEMFC system. Cs 2.5 H 0.5 PW 12 O 40 is insoluble in water and organic solvents and has micro-and mesopores with a high surface area ͑around 130 m 2 /g͒. 7 In addition, the acidity per unit acid site of Cs 2.5 H 0.5 PW 12 O 40 was superior to Nafion-H as well as homogeneous acids, e.g., H 2 SO 4 , H 3 PW 12 O 40 , and p-toluenesulfonic acid. 8 These facts demonstrate that Cs 2.5 H 0.5 PW 12 O 40 is a promising solid acid to be used in PEMFCs. Furthermore, Cs 2.5 H 0.5 PW 12 O 40 possesses a redox property. Various catalyzed reactions such as alkylation, ester decomposition, acylation, Diels-Alder reaction, have been reported to proceed on Cs 2.5 H 0.5 PW 12 O 40 . 9-11 Recently, Limoges et al. 12 reported the heterployacides can be used as the catalyst of the anode and cathode in PEMFCs.In view of the above strong acidic, hydrophilic, and redox properties of Cs 2.5 H 0.5 PW 12 O 40 , a high performance Cs 2.5 H 0.5 PW 12 O 40 /Nafion/PTFE self-humidifying composite membrane with a sandwich structure was developed to improve the mechanical strength of the membrane and the cell performance under lower RH condit...

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“…9,10. An aqueous solution of Cs 2 CO 3 was added dropwise to that of H 3 PW 12 O 40 , and the obtained precipitate was evaporated at 318 K followed by aging overnight.…”

Section: Methodsmentioning

confidence: 99%

“…Various catalyzed reactions such as alkylation, ester decomposition, acylation, Diels-Alder reaction, have been reported to proceed on Cs 2.5 H 0.5 PW 12 O 40 . [9][10][11] Recently, Limoges et al 12 reported the heterployacides can be used as the catalyst of the anode and cathode in PEMFCs.…”

mentioning

confidence: 99%

Self-Humidifying Cs2.5H0.5PW12O40 / Nafion / PTFE Composite Membrane for Proton Exchange Membrane Fuel Cells

Ming-qiang

Shao

Zhang

et al. 2006

Electrochemical and Solid-State Letters

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“…Owing to their strong acidities, heteropoly acids have been explored as potential catalysts for alkylation of isobutane with butene but the literature on this subject is scarce. 620,621 In these cases, K+, Rb+, Cs+, and NH4+ salts of tungstophosphoric heteropoly acid were preferred as catalysts and they could form tribranched products in good yields at relatively low temperatures (Table 23). Moreover, it appears that they give better results than superacid S042-/Zr02 catalysts.…”

Section: Inorganic Solid Acidsmentioning

confidence: 99%

Inorganic Solid Acids and Their Use in Acid-Catalyzed Hydrocarbon Reactions

Corma¹

1995

Chem. Rev.

3,023

1,890

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“…Because of their multifunctionality, heteropolyacids catalyze a wide variety of reactions including hydration and dehydration, condensation, reduction, oxidation, and carbonylation chemistry with Keggin-type anions of V, Mo [168], [169], [171][172][173]. A commercially important process, the oxidation of methacrolein, is catalyzed by a Cs salt of H 4 PVMo 11 O 40 .…”

Section: Vanadium Phosphatesmentioning

confidence: 99%

Heterogeneous Catalysis and Solid Catalysts

Knözinger¹,

Kochloefl²

2003

Ullmann's Encyclopedia of Industrial Chemistry

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Alkylation of Isobutane with Butenes Catalyzed by a Cesium Hydrogen Salt of 12-Tungstophosphoric Acid

Abstract: A solid superacid, Cs2.5H0.5PW12O40, catalyzed the alkylation of isobutane with butenes at room temperature. Cs2.5H0.5PW12O40 was much more active than SO42−/ZrO2, a well-known solid superacid, and was highly selective.

Cited by 70 publications

References 6 publications

Self-Humidifying Cs2.5H0.5PW12O40 / Nafion / PTFE Composite Membrane for Proton Exchange Membrane Fuel Cells

Self-Humidifying Cs2.5H0.5PW12O40 / Nafion / PTFE Composite Membrane for Proton Exchange Membrane Fuel Cells

Inorganic Solid Acids and Their Use in Acid-Catalyzed Hydrocarbon Reactions

Heterogeneous Catalysis and Solid Catalysts

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