Rub-10, a boron containing analogue of zeolite Nu-1.

Oberhagemann, U.; Marler, Β.; Topalović, Ivana; Gies, Hermann

doi:10.1016/s0167-2991(08)64143-9

Cited by 6 publications

(6 citation statements)

References 3 publications

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“…4) displays a single signal at 57.5 ppm, assigned to the methyl groups of TMA cations. This chemical shift is the same previously reported for RUB-10 synthesized in the presence of TMA [7], evidencing again the incorporation of this cation. Due to the high difficulty in calcining this material by conventional air thermal treatments, the organic material was more efficiently removed by ozone treatment.…”

Section: Bmpsupporting

confidence: 89%

Synthesis of Open Zeolite Structures from Mixtures of Tetramethylammonium and Benzylmethylalkylammonium Cations: A Step Towards Driving Aluminium Location in the Framework

et al. 2010

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Three bulky organic cations, benzylmethylpyrrolidinium (BMP), (S,S)-2-hydroxymethyl-1-benzyl-1-methylpyrrolidinium (BML) and benzylmethylhexamethyleniminium (BMH), were used in combination with the small cation tetramethylammonium (TMA) in the synthesis of zeolite materials. Two of them are distinguished by the number of carbon atoms forming the cyclic amine, which varies from 4 in BMP to 6 in BMH. In addition, a -CH 2 -OH group has been introduced in the carbon atom belonging to the amine ring next to the nitrogen atom, to originate a chiral molecule, BML, the third SDA used in this work. It has been found that the combination of the small TMA with those three bulkier SDAs, promotes the crystallization of zeolite structures that contain cages and channels. BMP leads to the crystallization of the 10-ring zeolite ferrierite, where TMA is located inside the ferrierite cage. If the size of the N-cyclic amine moiety increases, the resulting cation cannot be accommodated in the relatively narrow 10-ring channels of ferrierite, and in these cases the zeolite MCM-22 crystallizes. This zeolite contains large cages whose cross section is delimited by a 12-ring, where both BMH and BML can be easily accommodated. In this system, cage-like, chlatrasil type structures often co-crystallize with the open structures, evidencing that an appropriate balance between TMA and the bulky SDA is required to achieve the crystallization of open-frameworks. When BMP is used, mixtures of structurally related ferrierite and cage-like RUB-10 are obtained if an excess of TMA is present in the synthesis gel, while MCM-22 crystallizes together with the structurally related cage-like MTN phase.

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Section: Bmpsupporting

confidence: 89%

Synthesis of Open Zeolite Structures from Mixtures of Tetramethylammonium and Benzylmethylalkylammonium Cations: A Step Towards Driving Aluminium Location in the Framework

et al. 2010

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“…The doublet associated with trigonal boron disappears, whereas a sharp new peak at 19.5 ppm is displayed. This new isotropic signal may be due to a borate phase grafted onto the framework or hydrated extraframework boric acid 7 indicative of deboronation. Some framework tetrahedral boron is still evidenced by a peak at -2.7 ppm.…”

Section: Resultsmentioning

confidence: 99%

“…There is no doubt that the presence of these very large pores combined with acidic properties opens up new possibilities for processing and/or producing large molecules. Incorporation of foreign atoms in the framework of silica-based MCM-41 such as Al, [1][2][3] Ga, 4 Ti, 5 V, 6 and B [7][8][9] has been reported.…”

Section: Introductionmentioning

confidence: 99%

“…The substitution of Si by B during the synthesis of MCM-41 is expected to modify the acidic properties of these materials and thereby their catalytic properties. Recently, Oberhagemann et al 7 have reported the synthesis and characterization of boroncontaining MCM-41. The as-synthesized noncalcined samples were found to contain framework tetrahedral boron, whereas upon calcination, a fraction of the framework boron is converted to trigonal and extraframework species.…”

Section: Introductionmentioning

confidence: 99%

“…The as-synthesized noncalcined samples were found to contain framework tetrahedral boron, whereas upon calcination, a fraction of the framework boron is converted to trigonal and extraframework species. [7][8][9] In the case of microporous molecular sieves, the stability of framework boron in boron zeolites is established and depends on different treatments as well as the electrostatic character of the charge-compensating cation. Calcination of boron zeolites has generally been carried out in an oxidizing atmosphere, which causes high losses of framework boron (up to 66%).…”

Section: Introductionmentioning

confidence: 99%

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Synthesis, Stability and State of Boron in Boron-Substituted MCM-41 Mesoporous Molecular Sieves

Joshi

Kaliaguine

1996

J. Phys. Chem.

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The boron-substituted MCM-41 was hydrothermally synthesized using Na2B4O7 and H3BO3 as boron sources. The influence of the nature of the boron source on the textural properties as well as the stability of MCM-41 structure and the state of boron upon different procedures such as NH3 treatment, ion-exchange, and calcination were investigated using XRD, FTIR, TEM, and 11B MAS-NMR techniques. Na2B4O7 has proven its ability to improve uniform long-range ordering compared to the pure silica MCM-41 analogue. The order of the uniform hexagonal mesopores in the MCM-41 products obtained following the same synthesis conditions is B-MCM-41 prepared from Na2B4O7 > B-MCM-41 prepared from H3BO3 > pure silica MCM-41. The counterbalancing cations such as Na+ and NH4 + were found to be operative in stabilizing tetrahedral boron while H+ induces unstability. The ion-exchange procedures were found to be accompanied by a partial collapse of B-MCM-41 structure. The nature of counterbalancing cations was also found to play a role in deciding the state of boron and its stability during hydration/dehydration process.

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Direct methods structure determination from synchrotron powder diffraction data of a new clathrasil, TMA Silicate

Broach¹,

McGuire²,

Chao³

et al. 1995

Journal of Physics and Chemistry of Solids

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Rub-10, a boron containing analogue of zeolite Nu-1.

Cited by 6 publications

References 3 publications

Synthesis of Open Zeolite Structures from Mixtures of Tetramethylammonium and Benzylmethylalkylammonium Cations: A Step Towards Driving Aluminium Location in the Framework

Synthesis of Open Zeolite Structures from Mixtures of Tetramethylammonium and Benzylmethylalkylammonium Cations: A Step Towards Driving Aluminium Location in the Framework

Synthesis, Stability and State of Boron in Boron-Substituted MCM-41 Mesoporous Molecular Sieves

Direct methods structure determination from synchrotron powder diffraction data of a new clathrasil, TMA Silicate

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