Hydrothermal synthesis of metallosilicate SSZ-24 from metallosilicate beta as precursors

Kubota, Yoshihiro; Maekawa, Hiroyoshi; Miyata, Sumiko; Tatsumi, Takashi; Sugi, Yoshihiro

doi:10.1016/j.micromeso.2006.11.037

Cited by 45 publications

(32 citation statements)

References 42 publications

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“…To clarify the effect of structure defects on the acid stability, the chemical states of the silicon in the CHA type zeolites synthesized by interzeolite conversion and in SSZ-13 were investigated by 29 Si MAS NMR with and without 1 H _29 Si cross polarization (CP). Figure 10 shows the 29 Si MAS NMR spectra of CHA type zeolite and SSZ-13 43) . Three peaks were observed centered at (0Al), respectively.…”

Section: Acid Stabilitymentioning

confidence: 99%

High Potential of Interzeolite Conversion Method for Zeolite Synthesis

Sano

Itakura

Sadakane

2013

J. Jpn. Petrol. Inst.

101

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Many types of zeolites such as beta (hereinafter, BEA), CHA, LEV, RUT, and MFI were successfully synthesized by interzeolite conversion of FAU, BEA, and LEV type zeolites as starting materials under various hydrothermal synthesis conditions. The crystallization rates of zeolites using such starting zeolites were notably elevated compared to rates observed in conventional hydrothermal syntheses using amorphous aluminosilicate gels. This characteristic enhancement in the crystallization rate results from the generation of locally ordered aluminosilicate species (nanoparts) through the decomposition/dissolution of the starting zeolite, resulting in assembly and evolution into another type of zeolite. The structural similarity between the starting zeolite and the final crystallized zeolite is a crucial factor for interzeolite conversion. These findings strongly indicate that the interzeolite conversion route is an attractive strategy for zeolite synthesis and zeolite design will be possible after methods to selectively assemble the nanoparts are established.

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Section: Acid Stabilitymentioning

confidence: 99%

High Potential of Interzeolite Conversion Method for Zeolite Synthesis

Sano

Itakura

Sadakane

2013

J. Jpn. Petrol. Inst.

101

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“…17,18 Direct synthesis of Al-SSZ-24 was unsuccessful by a common hydrothermal method and could only be prepared with Al-BEA as the precursor through the phase transition method. 19,20 Up to now, research on the phase transformation mainly focused on the system of aluminosilicate zeolites, and less emphasis has been put upon SAPO molecular sieves. Chemistry of Materials ARTICLE is one of the most important members in the SAPO family, which has been recognized as a good catalyst for the methanol-to-olefin reaction with a high selectivity of ethene and propene.…”

Section: Introductionmentioning

confidence: 99%

Phase-Transformation Synthesis of SAPO-34 and a Novel SAPO Molecular Sieve with RHO Framework Type from a SAPO-5 Precursor

Tian

Wang

et al. 2011

Chem. Mater.

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SAPO-34 and a novel SAPO molecular sieve with the RHO framework (designated as DNL-6) were synthesized using SAPO-5 (the denser phase) as the precursor and diethylamine (DEA) as the template. The entire transition process had been investigated by XRD, SEM, XRF, and NMR spectroscopy, which clearly revealed a solution-mediated transport mechanism attributed to the transformation from SAPO-5 precursor to SAPO-34 via oscillating phases [SAPO-5 (FD = 16.9 T/nm 3 ) => SAPO-34 (15.1) þ DNL-6 (14.5) f DNL-6 f SAPO-34]. The initially formed SAPO-34 was different from the final one in this transformation due to very different percentages of organic inclusions, indicating that the host-guest interactions played important roles for the phase selectivity during the synthesis. DNL-6, obtained as an intermediate of the transformation process, possessed good thermal stability, large microporous surface area (724 m 2 /g), and high micropore volume (0.36 cm 3 /g). Rietveld refinement showed that the framework of calcined DNL-6 had typical features of the RHO structure with a high symmetry [I23, a = 15.08429(9) Å], composed of a body-centered cubic arrangement of R cages linked via double 8-rings.

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“…Since the first report of the hydrothermal conversion of zeolite A (LTA) into sodalite (SOD) and zeolite P (GIS) 24) 26) , this alternative method has attracted considerable attention. Hydrothermal conversion of a low density zeolite into a high-density zeolite is possible; for example, they transformed zeolite Y (FAU) transformed into SSZ-13 (CHA) 27) 33) . More recently, rapid crystallization of various zeolites was achieved from an FAU-type zeolite in the presence of a specific OSDA 34) 47) , including the successful transformation of the FAU phase into B E A 34) 36) , R U T 37), 38) , C H A 39) 41) , L E V 42) 44) , MTN 34), 45) , and OFF phases 46) .…”

Section: Hydrothermal Conversion Using Fau-typementioning

confidence: 99%