New Methods for Quantitative Determination of Brønsted Acid Sites on Solid Acids: Applicability and Limits for Al2O3-Promoted SO42−/ZrO2 Catalysts

Olindo, Roberta; Goeppert, Alain; Habermacher, David; Sommer, Jean; Pinna, Francesco

doi:10.1006/jcat.2000.3095

Cited by 38 publications

(28 citation statements)

References 17 publications

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“…However, it was often in powdered form with very poor mechanical properties; therefore, alumina must be added as a binder in industrial catalyst preparation. It was then discovered that introduction of alumina could markedly improve the catalyst performance [4][5][6]. Moreover, it is reported that promotion of platinum to SZ in PSZ preparation would not only inhibit the formation of coke improving the stability but also results in high steady yields of isomers in n-C 5 /n-C 6 hydroisomerization [7,8].…”

Section: Introductionmentioning

confidence: 99%

On the Role of Calcination Temperature in Pt-SO 4 2− /ZrO2−Al2O3 Preparation and Catalytic Behaviors During the n-Hexane Hydroisomerization

Zhou

Tang

et al. 2008

Catal Lett

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Effects of calcination temperature for Pt-SO 4 2-/ ZrO 2 -Al 2 O 3 (PSZA) catalysts in n-hexane hydroisomerization were investigated by N 2 -adsorption, XRD, TG-DTA, FTIR, XPS and H 2 -TPR. An optimum calcination temperature is helpful to complete the crystallization process, resulting in better distribution of alumina into zirconia crystal and producing new acid centers responsible for higher catalytic activity.

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Section: Introductionmentioning

confidence: 99%

On the Role of Calcination Temperature in Pt-SO 4 2− /ZrO2−Al2O3 Preparation and Catalytic Behaviors During the n-Hexane Hydroisomerization

Zhou

Tang

et al. 2008

Catal Lett

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“…Silicon has not been used as a minority species in SZ, i.e. as a promoter, while aluminum-promoted SZ [63] was tested in n-butane [64][65][66][67][68][69], isobutane [70,71], and n-pentane isomerization [64], and benzoylation of toluene with benzoyl chloride [64,72].…”

Section: Introductionmentioning

confidence: 99%

n-Butane Isomerization Catalyzed by Sulfated Zirconia Nanocrystals Supported on Silica or γ-Alumina

Yang

Jentoft

2006

Catal Lett

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Supported sulfated zirconia catalysts with zirconia contents of 10, 20 and 50 wt% were prepared by impregnation of SiO 2 and γ-Al 2 O 3 supports with H 2 SO 4 /Zr(SO 4 ) 2 solutions followed by calcination at 923 K. The catalysts were characterized by X-ray diffraction, extended X-ray absorption fine structure measurements, thermal analysis, UV-vis spectroscopy, and electron microscopy. Tetragonal zirconia was detected in all silicasupported samples but only in the 50 wt % zirconia-containing alumina-supported sample, indicating high dispersion of zirconia on alumina. Alumina-supported samples retained additional sulfate, at least in part as Al 2 (SO 4 ) 3 . All samples were active in n-butane isomerization (1kPa nbutane, 378 K). There was no relation between the presence of tetragonal zirconia in these samples and the catalytic performance.

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“…Neither the b-methylene protons nor the more accessible terminal methyl group were involved in the H/D exchange. Again, as a result of the isotope effect on chemical shifts, [47][48][49] various isotopologues are observed in the early stages of the exchange process: Three peaks assigned to CDH 2 , CD 2 H, and CD 3 for the methyl group and two peaks assigned to CDH and CD 2 for the a-methylene group (Figure 2b).…”

Section: Resultsmentioning

confidence: 98%

“…150 mL, 1.1 mmol in the case of 2MP, 145 mL, 1.1 mmol of 3MP, 143 mL, 1.1 mmol of n-hexane, 34 mL (gas), 1.5 mmol of isobutene, and 6 % butane in N 2 ) was introduced into the recirculation loop. The amount of protons provided by the hydrocarbon was in large excess compared with the acid deuterons because the concentrations of the D 2 O-exchanged acid sites at 200 8C, as determined by the NMR method, [49,50] were found to be 4.4, 1.9, and 1.0 mmol H + g À1 for USY, MOR, and ZSM5, respectively. The gas-phase mixture (hydrocarbon and nitrogen) was circulated by a membrane pump at a recirculation rate of 20 mL min…”

Section: Full Papermentioning

confidence: 97%

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Room‐Temperature Alkane Reactivity in Zeolites: An H/D Exchange Study

Sido

Walspurger

Barbiche

et al. 2010

Chemistry A European J

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As evidenced by H/D exchange with acidic zeolites, isoalkanes react readily at room temperature whereas linear alkanes do not. The observed regioselectivity of the exchange process demonstrates that the main factor controlling the reaction is not the accessibility to the acid sites, but the intrinsic reactivity of the alkane. The mechanism is best rationalized by classic organic chemistry involving carbocationic intermediates including the Markovnikov rule.

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New Methods for Quantitative Determination of Brønsted Acid Sites on Solid Acids: Applicability and Limits for Al2O3-Promoted SO42−/ZrO2 Catalysts

Cited by 38 publications

References 17 publications

On the Role of Calcination Temperature in Pt-SO 4 2− /ZrO2−Al2O3 Preparation and Catalytic Behaviors During the n-Hexane Hydroisomerization

On the Role of Calcination Temperature in Pt-SO 4 2− /ZrO2−Al2O3 Preparation and Catalytic Behaviors During the n-Hexane Hydroisomerization

n-Butane Isomerization Catalyzed by Sulfated Zirconia Nanocrystals Supported on Silica or γ-Alumina

Room‐Temperature Alkane Reactivity in Zeolites: An H/D Exchange Study

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