Super acidity confirmed on a monolayer of sulfate species loaded on zirconia

Katada, Naonobu; Endo, Jun-ichi; Notsu, Kei-ichi; Yasunobu, Naoko; Naito, Norihiro; Niwa, Miki

doi:10.1016/s0167-2991(00)80517-0

Cited by 10 publications

(10 citation statements)

References 16 publications

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“…The calculated heats of adsorption of various solid acids are summarized in Table along with the heat of NH 3 adsorption and the activation energy of Ar desorption measured by Ar-TPD . The order of the adsorption heats is as follows: The order of heat of SiO 2 −Al 2 O 3 , zeolites, and SO 4 2- /ZrO 2 measured in this study was consistent with that of acid strength evaluated by the heat of NH 3 adsorption 7 and Ar-TPD .…”

Section: Resultssupporting

confidence: 77%

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Measurement of Heat of Argon Adsorption for the Evaluation of Relative Acid Strength of Some Sulfated Metal Oxides and H-type Zeolites

2001

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The relative acid strength of sulfated SnO2, sulfated ZrO2, silica−alumina, H−Y, H−ZSM-5, and H-mordenite was estimated by the heat of Ar adsorption, calculated from a temperature dependence of amount of Ar adsorption around room temperature. These were 23.5, 23.6, and 13.8−16.5 kJ mol-1 for sulfated SnO2, sulfated ZrO2, and H-type zeolites, respectively. The data indicate that Ar is suitable for a probe molecule of acid sites on solid surface and that this technique is useful for evaluation of the acid strength of solid superacids.

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Section: Resultssupporting

confidence: 77%

“…The calculated heats of adsorption of various solid acids are summarized in Table 1 along with the heat of NH 3 adsorption 7 and the activation energy of Ar desorption measured by Ar-TPD. 4 The order of the adsorption heats is as follows:…”

Section: Resultsmentioning

confidence: 99%

Measurement of Heat of Argon Adsorption for the Evaluation of Relative Acid Strength of Some Sulfated Metal Oxides and H-type Zeolites

2001

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“…The order of heat of the SA, zeolite, and SZ samples measured in this study was consistent with that of the acid strength evaluated from Ar-TPD, 17 NH 3 -TPD, 1,25,26 and heat of adsorption of NH 3 measurements. 27 This result indicates that the adsorbed Ar has an acid-base-like interaction with the acid sites on the samples' surface. Therefore, it can be stated that the relative acid strength of the solid acids can be evaluated from the heat of Ar adsorption obtained from Langmuir-type adsorption isotherms.…”

Section: L-methodsmentioning

confidence: 91%

Measurement of the relative acid strength and acid amount of solid acids by argon adsorption

Matsuhashi

Arata

2004

Phys. Chem. Chem. Phys.

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“…Cheung and co-workers , suggested that sulfated zirconia is a stronger acid than USY zeolite, because it has a higher effectiveness in alkane protonation. The adsorption heat of ammonia , and Ar , also demonstrated stronger acidity of sulfated zirconia than that of zeolites (H-MOR, H-ZSM-5, and H–Y). However, the superacidity of sulfated zirconia has been challenged by the questionable measurement of Hammett acidity functions for solids .…”

Section: Introductionmentioning

confidence: 94%

Effect of Aluminum Addition and Surface Moisture Content on the Catalytic Activity of Sulfated Zirconia in n-Butane Isomerization

Wang

Yang

et al. 2019

Ind. Eng. Chem. Res.

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The effects of aluminum addition and surface moisture on the surface-structure properties and catalytic activity of sulfated zirconia were investigated in n-butane isomerization. Adding 4 mol % Al into zirconia support with coprecipitation method greatly improves the catalytic activity. This is attributed to the monolayer coverage of sulfate species and the maximum of Brønsted acid sites, resulting from the strongly stabilized sulfate species on the tetragonal zirconia (t-ZrO2) surface. The in situ DRIFTS investigations and density functional theory (DFT) calculations show that the dehydration temperature affects both the density and the strength of Brønsted acid sites, and there is a balance between them. The optimal catalytic activity is reached with complete desorption of physical adsorbed water and partial desorption of surface hydroxyl groups. The strongly stabilized sulfate species on appropriately dehydrated surface of t-ZrO2 provide the superacidity and the strong oxidizing ability via a strong electron-withdrawing effect of SO bonds.

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Super acidity confirmed on a monolayer of sulfate species loaded on zirconia

Cited by 10 publications

References 16 publications

Measurement of Heat of Argon Adsorption for the Evaluation of Relative Acid Strength of Some Sulfated Metal Oxides and H-type Zeolites

Measurement of Heat of Argon Adsorption for the Evaluation of Relative Acid Strength of Some Sulfated Metal Oxides and H-type Zeolites

Measurement of the relative acid strength and acid amount of solid acids by argon adsorption

Effect of Aluminum Addition and Surface Moisture Content on the Catalytic Activity of Sulfated Zirconia in n-Butane Isomerization

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