Expressiveness of Adsorption Measurements for Characterization of Zeolitic Materials—A Review

Kornatowski, J.

doi:10.1007/s10450-005-5397-6

Cited by 7 publications

(5 citation statements)

References 55 publications

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“…These cations can move freely along the diffusion paths formed by voids and channels in the zeolite structure, and are responsible for the ion conducting properties of zeolites [22]. Zeolites are highly hydrophilic solids and have a high water sorption capacity because of the charged anionic framework and the extra-framework cations [23,24] in addition to their open structure, high pore volume and surface area.…”

Section: Introductionmentioning

confidence: 99%

On the proton conductivity of Nafion–Faujasite composite membranes for low temperature direct methanol fuel cells

Zhang

Désilets

Felice

et al. 2011

Journal of Power Sources

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a b s t r a c tAlthough zeolites are introduced to decrease methanol crossover of Nafion membranes for direct methanol fuel cells (DMFCs), little is known about the effect of their intrinsic properties and the interaction with the ionomer. In this work, Nafion-Faujasite composite membranes prepared by solution casting were characterized by extensive physicochemical and electrochemical techniques. Faujasite was found to undergo severe dealumination during the membrane activation, but its structure remained intact. The zeolite interacts with Nafion probably through hydrogen bonding between Si-OH and SO 3 H groups, which combined with the increase of the water uptake and the water mobility, and the addition of a less conductive phase (the zeolite) leads to an optimum proton conductivity between 0.98 and 2 wt% of zeolite. Hot pressing the membranes before their assembling with the electrodes enhanced the DMFC performance by reducing the methanol crossover and the serial resistance.

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Section: Introductionmentioning

confidence: 99%

On the proton conductivity of Nafion–Faujasite composite membranes for low temperature direct methanol fuel cells

Zhang

Désilets

Felice

et al. 2011

Journal of Power Sources

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“…Role of Water on EtO Removal. H 2 O adsorption in acidified ZSM-5 has been extensively investigated both experiment-ally ,− ,− and computationally , due to its importance in a wide range of acid-catalyzed reactions. Water adsorbs strongly onto Brønsted acid centers associated with H−ZSM-5, leading to a linear relationship between the amount of adsorbed water and the aluminum content of the zeolite. ,,, For example, Sano et al reported water adsorption isotherms at 25 °C for H−ZSM-5 crystals with SiO 2 /Al 2 O 3 ratios between 71 and 3300.…”

Section: Resultsmentioning

confidence: 99%

“…H 2 O adsorption in acidified ZSM-5 has been extensively investigated both experiment-ally ,− ,− and computationally , due to its importance in a wide range of acid-catalyzed reactions. Water adsorbs strongly onto Brønsted acid centers associated with H−ZSM-5, leading to a linear relationship between the amount of adsorbed water and the aluminum content of the zeolite. ,,, For example, Sano et al reported water adsorption isotherms at 25 °C for H−ZSM-5 crystals with SiO 2 /Al 2 O 3 ratios between 71 and 3300. The authors noted (1) a linear increase in the amount of adsorbed water with increased partial pressure and (2) the strong dependency on the amount of adsorbed water and the SiO 2 /Al 2 O 3 ratio.…”

Section: Resultsmentioning

confidence: 99%

H−ZSM-5 for the Removal of Ethylene Oxide: Effects of Water on Filtration Performance

Peterson

Karwacki

Feaver

et al. 2007

Ind. Eng. Chem. Res.

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Zeolite H−ZSM-5 with a SiO2/Al2O3 ratio of 25 was evaluated for its ability to remove ethylene oxide (EtO) from streams of air at 25 °C and between 15 and 90% relative humidity (RH). The primary mechanism for the removal of ethylene oxide using H−ZSM-5 involves a catalyzed hydrolysis reaction initiated by the adsorption of EtO onto a Brønsted acid site. Secondary addition reactions leading to the formation of polyglycols are also occurring. The reaction is poisoned by the accumulation of reaction products within the pores of the zeolite, which ultimately leads to elution of EtO from the filter bed. The ability of H−ZSM-5 to remove EtO decreased significantly as the relative humidity increased from 50 to 90%. For example, the EtO breakthrough time decreases from 220 min at 50% RH to 57 min at 90% RH. The decrease in the EtO breakthrough time over the stated RH range is attributed to the increased hydration of the Brønsted acid site. As the extent of Brønsted acid site hydration increases, the reactivity of the site is reduced, leading to a reduction in the EtO breakthrough time.

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“…For crystalline zeolites as micro- porous sorbents, sorption isotherms of type I are typically expected (Barrer 1978;Kornatowski 2005). Such isotherms are characterized under very low P /P 0 by very high Vs, corresponding to sorbate molecule binding in micropores, and further by Vs "saturation" (plateau area of an isotherm) (Gregg and Sing 1982;Aranovich and Donohue 1998).…”

Section: Sorption Isothermsmentioning

confidence: 98%

Adsorption of volatile hydrocarbons on natural zeolite-clay material

et al. 2008

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This study investigated the vapor-phase sorption of hydrocarbons (HC) of various chemical nature (n-hexane, iso-octane, benzene, toluene and p-xylene) on zeolite-clay material (ZCM) of Tatarsky-Shatrashansky deposit (Tatarstan, Russia). For comparison, we also studied HC sorption on natural high-grade zeolite (Z) of St. Cloud Mine (New Mexico, USA), two local bentonite clays and synthetic zeolite-molecular sieve Ms5A. As a result, sorption capacity of ZCM towards aliphatic and aromatic HC was significantly higher than the sorption capacity of Z but lower than that of clays. In addition, the data showed that HC sorption on ZCM occurs as surface adsorption. The comparison with Ms5A and erionite ZAPS, a natural Mexican zeolite, revealed that both ZCM and Z do not interact as microporous selective sorbents with linear alkanes. The main differences in HC sorption on ZCM and Z were ZCM higher sorption capacity towards both aliphatic and aromatic HC, as well as its lower sorption sensitivity to the type of HC. We found that the reason for these differences is the presence of large amount of clay minerals in ZCM. To summarize, ZCM can be considered as a suitable adsorbent for protection and remediation of HC-contaminated soils. NomenclatureHC hydrocarbons ZCM natural zeolite-clay material Z natural zeolite of St. Cloud Mine I. Breus ( ) · A. Denisova · S. Nekljudov · V. Breus

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Expressiveness of Adsorption Measurements for Characterization of Zeolitic Materials—A Review

Cited by 7 publications

References 55 publications

On the proton conductivity of Nafion–Faujasite composite membranes for low temperature direct methanol fuel cells

On the proton conductivity of Nafion–Faujasite composite membranes for low temperature direct methanol fuel cells

H−ZSM-5 for the Removal of Ethylene Oxide: Effects of Water on Filtration Performance

Adsorption of volatile hydrocarbons on natural zeolite-clay material

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