Vibrational spectroscopic study of the evolution of the framework of the zeolite ferrierite

Dutta, Prabir K.; Rao, K. Mallikarjuna; Park, Jong Yul

doi:10.1021/la00038a068

Cited by 20 publications

(15 citation statements)

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“…Of the five zeolite topologies that dominate the commercial zeolite catalyst production -FAU, MFI, *BEA, MOR and FER [4]-Beta was for a long time the only one that could not be obtained synthetically in the absence of an OSDA [1,34,35]. It should be noted, however, that the addition of OSDA can significantly speed up the crystallization process or may still be required to obtain alternative framework compositions for the above-mentioned topologies [28,36]. An indication that OSDAs are not strictly indispensable for Beta zeolite synthesis, appeared with the discovery of Tschernichite, the natural mineral analogue of Beta zeolite [37].…”

Section: Osda-free Synthesis Of Beta Zeolitementioning

confidence: 99%

Catalytic applications of OSDA-free Beta zeolite

Baerdemaeker

Yilmaz

Müller

et al. 2013

Journal of Catalysis

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Zeolite Beta obtained from seeded synthesis without the use of organic structure directing agents (OSDA) has been used as a catalyst in different types of reactions. The large number of strong acid sites resulted in a high activity for the alkylation of benzene with ethene and a high cracking activity in the hydroconversion of n-decane. However, the high framework polarity resulted in fast deactivation in the acylation of aromatic ethers. Dealumination treatments resulted in improved stability in alkylation reactions with the more reactive olefins like propene. In acylation reactions, the activity was significantly increased and in hydroconversion, a better balance between the hydrogenation/dehydrogenation and the acid sites was obtained.

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Section: Osda-free Synthesis Of Beta Zeolitementioning

confidence: 99%

Catalytic applications of OSDA-free Beta zeolite

Baerdemaeker

Yilmaz

Müller

et al. 2013

Journal of Catalysis

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“…They proposed that all T-O-T bonds are contributing to the most prominent band in the region of 300-600 cm À1 [67]. What's more, the frequency of the most prominent band is sensitive to the ring structures present in the material, with an inverse correlation between the frequency and the average T-O-T angle [24]. For example, anorthite-like glasses with predominantly 4Rs exhibit a band at 500-510 cm À1 , whereas for nepheline glass with 6Rs, a band below 470 cm À1 is observed [24].…”

Section: 2mentioning

confidence: 99%

“…In the case of mordenite, 4Rs are observed at the early stage followed by a ''mordenite-like'' amorphous phase with disordered 4Rs and 5-membered rings (5Rs), which then quickly connect to form mordenite crystals [7]. Dutta et al have also used Raman spectroscopy to study the formation mechanisms of zeolite A [22], ZSM-5 [23] and ferrierite [24].…”

Section: Introductionmentioning

confidence: 99%

Changes of medium-range structure in the course of crystallization of zeolite omega from magadiite

Cui

Zhang

Liu

et al. 2014

Microporous and Mesoporous Materials

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“…Raman spectroscopy has been extensively employed to gain comprehensive structural information of various zeolitetype and feldspar-type aluminosilicate materials (e.g., Dutta , 1992Smirnov et al 1994;Wopenka et al 1998;Goryainov and Smirnov 2001;Yu et al 2001;Mozgawa et al 2004;Putnis et al 2007;Fisch et al 2008;Liu et al 2012). Presented in Figure 6 is the Raman spectrum of rongibbsite.…”

Section: Raman Spectramentioning

confidence: 99%

“…In contrast, for materials containing isolated TO 4 tetrahedra, the Raman bands caused by T-O symmetric stretching modes are typically much stronger than the ones arising from T-O asymmetric stretching modes. It has been well established that the wavenumbers of Raman bands attributable to the T-O-T bending modes are inversely correlated to the tetrahedral ring size or the average <T-O-T> angle for a given tetrahedral ring, as well as the Si/Al ratio (e.g., Dutta et al 1992;Wopenka et al 1998;Yu et al 2001). In particular, based on the UV Raman spectroscopic measurements, Yu et al (2001) demonstrated that the Raman bands at 470-530, 370-430, 290-410, and 220-280 cm -1 can be assigned to the bending modes of 4-, 5-, 6-, and 8-membered rings of aluminosilicate zeolites, respectively.…”

Section: Raman Spectramentioning

confidence: 99%

Rongibbsite, Pb2(Si4Al)O11(OH), a new zeolitic aluminosilicate mineral with an interrupted framework from Maricopa County, Arizona, U.S.A.

Yang

Downs

Evans

et al. 2012

American Mineralogist

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A new zeolitic aluminosilicate mineral species, rongibbsite, ideally Pb 2 (Si 4 Al)O 11 (OH), has been found in a quartz vein in the Proterozoic gneiss of the Big Horn Mountains, Maricopa County, Arizona, U.S.A. The mineral is of secondary origin and is associated with wickenburgite, fornacite, mimetite, murdochite, and creaseyite. Rongibbsite crystals are bladed (elongated along the c axis, up to 0.70 × 0.20 × 0.05 mm), often in tufts. Dominant forms are {100}, {010}, {001}, and {101}. Twinning is common across (100). The mineral is colorless, transparent with white streak and vitreous luster. It is brittle and has a Mohs hardness of ∼5; cleavage is perfect on {100} and no parting was observed. The calculated density is 4.43 g/cm 3 . Optically, rongibbsite is biaxial (+), with n α = 1.690, n β = 1.694, n γ = 1.700, c Z = 26°, 2V meas = 65(2)°. It is insoluble in water, acetone, or hydrochloric acid. Electron microprobe analysis yielded an empirical formula Pb 2.05 (Si 3.89 Al 1.11 )O 11 (OH).Rongibbsite is monoclinic, with space group I2/m and unit-cell parameters a = 7.8356 (6), b = 13.913(1), c = 10.278(1) Å, β = 92.925(4)°, and V = 1119.0(2) Å 3 . Its structure features an interrupted framework made of three symmetrically distinct TO 4 tetrahedra (T = Si + Al). The framework density is 17.9 T per 1000 Å 3 . Unlike many known interrupted frameworks in zeolite-type materials, which are usually broken up by OH or F, the framework in rongibbsite is interrupted by O atoms. There are various corner-shared tetrahedral rings in the framework of rongibbsite, including two types of 4-membered, three 6-membered, and one 8-membered rings. The extraframework Pb and OH reside alternately in the channels formed by the 8-membered rings. The Pb cations are disordered over two split sites, Pb and Pb′, with site occupancies of 0.8 and 0.2, respectively, and a Pb-Pb′ distance of 0.229 Å, providing a structural explanation for the two strong Raman bands (at 3527 and 3444 cm -1 ) attributable to the O-H stretching vibrations. The average bond lengths for the T1, T2, and T3 tetrahedra are 1.620, 1.648, and 1.681 Å, respectively, indicating that the preference of Al for the three tetrahedral sites is T3 >> T2 > T1. Rongibbsite represents the first natural aluminosilicate with Pb as the only extraframework cation.

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Vibrational spectroscopic study of the evolution of the framework of the zeolite ferrierite

Cited by 20 publications

References 0 publications

Catalytic applications of OSDA-free Beta zeolite

Catalytic applications of OSDA-free Beta zeolite

Changes of medium-range structure in the course of crystallization of zeolite omega from magadiite

Rongibbsite, Pb2(Si4Al)O11(OH), a new zeolitic aluminosilicate mineral with an interrupted framework from Maricopa County, Arizona, U.S.A.

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