A New Approach to the Determination of the External Surface and Micropore Volume of Zeolites from the Nitrogen Adsorption Isotherm at 77 K

Remy, M.; Poncelet, Georges

doi:10.1021/j100002a047

Cited by 100 publications

(67 citation statements)

References 4 publications

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“…This effect can be ascribed, as already evidenced (45), to the formation of mesopores during dealumination that may be accompanied by the collapse of some micropore blocking. The surface areas of Mo dealuminated samples were higher than those of Mofree ones, indicating that some of the deposited Mo species in mesopores are responsible for the marked increase in S BET probably due to the formation of their own texture.…”

Section: Surface Properties Crystallinity and Water Content Of The supporting

confidence: 52%

Effect of Mordenite Dealumination on the Structure of Encapsulated Molybdenum Catalysts

Mohamed

Salama

2002

Journal of Colloid and Interface Science

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Section: Surface Properties Crystallinity and Water Content Of The supporting

confidence: 52%

Effect of Mordenite Dealumination on the Structure of Encapsulated Molybdenum Catalysts

Mohamed

Salama

2002

Journal of Colloid and Interface Science

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“…S4), which is present in all conventional zeolite samples, as compared with ZSM-5 (ref. 31). The hysteresis loop of SCZN-1 at a relative pressure range of 0.5-1.0 shows a few amount and random distribution of mesopores due to the interconnected single-crystalline pore system and some polycrystalline pores formed by random aggregation of the thin petals.…”

Section: Resultsmentioning

confidence: 94%

“…Figure 5 shows the N 2 desorptiondesorption isotherms of calcined samples by BC Ph-n-6-6 . All samples show the uptake steps below P/P 0 ¼ 0.02 due to the microporous MFI structure 31 , while only the samples templated by BC Ph-6-6-6 and BC Ph-8-6-6 exhibit a higher uptake at a relative pressure range of 0.2-0.8 due to the presence of abundant and uniform mesopores after calcination. The capillary condensation loop at P/P 0 ¼ 0.1-0.3 reveals the presence of small mesopores formed by the collapse of the lamellar structure near the joints (Fig.…”

Section: Resultsmentioning

confidence: 97%

π–π interaction of aromatic groups in amphiphilic molecules directing for single-crystalline mesostructured zeolite nanosheets

et al. 2014

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One of the challenges in material science has been to prepare macro-or mesoporous zeolite. Although examples of their synthesis exist, there is a need for a facile yet versatile approach to such hierarchical structures. Here we report a concept for designing a single quaternary ammonium head amphiphilic template with strong ordered self-assembling ability through p-p stacking in hydrophobic side, which stabilizes the mesostructure to form singlecrystalline mesostructured zeolite nanosheets. The concept is demonstrated for the formation of a new type of MFI (zeolite framework code by International Zeolite Association) nanosheets joined with a 90°rotational boundary, which results in a mesoporous zeolite with highly specific surface area even after calcination. Low binding energies for this selfassembling system are supported by a theoretical analysis. A geometrical matching between the arrangement of aromatic groups and the zeolitic framework is speculated for the formation of single-crystalline MFI nanosheets.

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“…In the t-plot of de Boer et al, the adsorbed N2 volume (V) is plotted against the statistical thickness (t) of the adsorbed N2 layer to yield the micropore volumes and nonporous surface areas of solids on the basis that (Remy and Poncelet 1995):…”

Section: Theoretical Considerationmentioning

confidence: 99%

Effects of Exchanged Cation on the Microporosity of Montmorillonite

Rutherford

Chiou

Eberl

1997

Clays and clay miner.

120

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Abstract--The micropore volumes of 2 montmorillonites (SAz-1 and SWy-1), each exchanged with Ca, Na, K, Cs and tetramethylammonium (TMA) ions, were calculated from the measured vapor adsorption data of N 2 and neo-hexane by use of t-and a~-plots. The corresponding surface areas of the exchanged clays were determined from Brunauer-Emmett-Teller (BET) plots of N 2 adsorption data. Micropore volumes and surface areas of the samples increased with the size of exchanged cation: TMA > Cs > K > Ca > Na. The SAz-1 exchanged clays showed generally greater micropore volumes and surface areas than the corresponding SWy-1 clays. The vapor adsorption data and d(001) measurements for dry clay samples were used together to evaluate the likely locations and accessibility of clay micropores, especially the relative accessibility of their interlayer spacing. For both source clays exchanged with Na, Ca and K ions, the interlayer spacing appeared to be too small to admit nonpolar gases and the accessible micropores appeared to have dimensions greater than 5.0 .~, the limiting molecular dimension of neo-hexane. In these systems, there was a good consistency of micropore volumes detected by N2 and neo-hexane. When the clays were intercalated with relatively large cations (TMA and possibly Cs), the large layer expansion created additional microporosity, which was more readily accessible to small N: than to relatively large neo-hexane. Hence, the micropore volume as detected by N 2 was greater than that detected by neo-hexane. The micropore volumes with pore dimensions greater than 5 A determined for clays exchanged with Na, Ca and K likely resulted from the pores on particle edges and void created by overlap regions of layers. The increase in micropore volumes with pore dimensions less than 5 A determined for clays exchanged with TMA and possibly Cs could be caused by opening of the interlayer region by the intercalation of these large cations.

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A New Approach to the Determination of the External Surface and Micropore Volume of Zeolites from the Nitrogen Adsorption Isotherm at 77 K

Cited by 100 publications

References 4 publications

Effect of Mordenite Dealumination on the Structure of Encapsulated Molybdenum Catalysts

Effect of Mordenite Dealumination on the Structure of Encapsulated Molybdenum Catalysts

π–π interaction of aromatic groups in amphiphilic molecules directing for single-crystalline mesostructured zeolite nanosheets

Effects of Exchanged Cation on the Microporosity of Montmorillonite

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