Influence of solid-state transformation time on the nucleation and growth of silicalite 1 prepared from layered silicate

Salou, M.; Kiyozumi, Yoshimichi; Mizukami, Fujio; Nair, Padmakumar; Maeda, Kazuyuki; Niwa, Shu‐ichi

doi:10.1039/a803085e

Cited by 46 publications

(31 citation statements)

References 11 publications

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“…The similar observation was seen in the synthesis of MgAPO-36 synthesis. 20,21) ZnO/Al 2 O 3 ratio in the initial gel composition influenced the crystallization of ZnAPO-36 ( Table 2, entries [16][17][18][19][20][21]. The ratio between 0.1-0.25 gave pure phase ( Table 2, entries 16-18, 20, and 21); however, the increase of the ratio to 0.43 resulted in contamination with impurities ( Table 2, entry 19).…”

Section: Zincoaluminophosphate Molecular Sieves With Afi and Ats Topomentioning

confidence: 99%

“…[12][13][14][15][16][17] In comparison with the conventional hydrothermal synthesis method, these new methods have the advantages for environmental conscious synthesis of molecular sieves: the expansion of chemical compositions, the reduction of the SDA concentration, high conversion of gel, formation of uniform fine particles with high crystallization, minimization of waste disposal etc. [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Dry-gel conversion (DGC) method is a synthetic technique using dry gel without bulk aqueous phase, [12][13][14] and is classified to two different but interrelated methods: vapor-phase transport (VPT, as used by Kim et al) 12) and steam-assisted conversion (SAC, as used by Matsukata et al) 13,14) methods. We recently described the convenient synthesis of maganesioaluminophosphates with AFI and ATS topologies.…”

Section: Introductionmentioning

confidence: 99%

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Zincoaluminophosphate Molecular Sieves with AFI and ATS Topologies: Synthesis by Dry-Gel Conversion Methods and Their Catalytic Properties in the Isopropylation of Biphenyl

et al. 2005

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Zincoaluminophosphates, ZnAPO-5 and ZnAPO-36 with AFI and ATS topologies, were successfully synthesized by dry-gel conversion (DGC) method: vapor-phase transport (VPT) and steam-assisted conversion (SAC) methods. ZnAPO-5 was synthesized successfully at 175 C by VPT and SAC methods using Et 3 N as structure directing agent (SDA). ZnAPO-36 was also obtained by VPT and SAC methods using Pr 3 N as SDA. The heating protocol was a key factor for the crystallization in the synthesis of ZnAPO-36: the best result was obtained by heating at 140 C for 1 d after aging of the gel at 105 C for 2 d. Calcination procedure is important to get microporous molecular sieves. ZnAPO-5 by VPT method calcined at 550 C gave clear XRD with high microporosity. Highly microporous ZnAPO-36 by VPT method was obtained by careful calcination. Characterization of these zincoaluminophosphates was performed by XRD, NH 3 -TPD, TG, SEM, N 2 adsorption, and ICP analysis. ZnAPO-5 and ZnAPO-36 have the Brønsted acidic characters by the substitution of a part of aluminum with zinc.The isopropylation of biphenyl (BP) over these molecular sieves gave different level of the selectivities for 4,4 0 -DIPB: 60-75% for ZnAPO-5 and 35-45% for ZnAPO-36: these selectivities are in the similar level to corresponding magnesioaluminophosphates corresponding magnesioaluminophosphates. These differences of in the selectivity are due to the pore structure: ZnAPO-5 has onedimensional straight channel; however, ZnAPO-36 has one-dimensional channel with side pocket. The steric restriction by ZnAPO-5 effectively controls the transition state to differentiate the slim isomers from others; however, pores of ZnAPO-36 cannot differentiate effectively the isomers because of their side pockets.

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Section: Zincoaluminophosphate Molecular Sieves With Afi and Ats Topomentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Zincoaluminophosphate Molecular Sieves with AFI and ATS Topologies: Synthesis by Dry-Gel Conversion Methods and Their Catalytic Properties in the Isopropylation of Biphenyl

et al. 2005

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“…In 1996, Kiyozumi and co-workers introduced a solid-state method for the synthesis of silicalite-1 and silicalite-2 via the transformations of kanemite intercalated with tetrapropylammonium (kanemite-TPA) and tetrabutylammonium (kanemite-TBA) cations, respectively. [60][61][62] In comparison with the conventional synthesis of zeolites, the main advantages of this method are shorter crystallization time, smaller crystals and a convenient way to prepare binder-free pre-shaped zeolites in different forms ( pellets and discs). This method of preparation has been extended to the synthesis of various other zeolite types including Al-MFI, 63 Cu-and Co-silicalite-1, 64 and FER.…”

Section: Transformation Of Layered Silicates Into Zeolitesmentioning

confidence: 99%

Reactivity and applications of layered silicates and layered double hydroxides

2014

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Layered materials, such as layered sodium silicates and layered double hydroxides (LDHs), are well-known for their remarkable adsorption, intercalation and swelling properties. Their tunable interlayers offer an interesting avenue for the fabrication of pillared nanoporous materials, organic-inorganic hybrid materials and catalysts or catalyst supports. This perspective article provides a summary of the reactivity and applications of layered materials including aluminium-free layered sodium silicates (kanemite, ilerite (RUB-18 or octosilicate) and magadiite) and layered double hydroxides (LDHs). Recent developments in the use of layered sodium silicates as precursors for the preparation of various porous, functional and catalytic materials including zeolites, mesoporous materials, pillared layered silicates, organic-inorganic nanocomposites and synthesis of highly dispersed nanoparticles supported on silica are reviewed in detail. Along this perspective, we have attempted to illustrate the reactivity and transformational potential of LDHs in order to deduce the main differences and similarities between these two types of layered materials.

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“…The crystallization of MWW phase was started after 1 d among amorphous phase. Amorphous phase was completely converted to MWW phase after two days, and the pure MWW was obtained after crystallization for 4 d. The amount of seeds was varied from 0.125 to 2.0 mass% against SiO 2 in the synthesis of MWW as in Table 2 (entries 20, [24][25][26][27][28], and the XRD patterns are shown in Fig. 4.…”

Section: Seeding On the Synthesis Of Mwwmentioning

confidence: 99%

“…13) New methods of zeolite synthesis, such as a dry-gel conversion (DGC) method and solid transformation have been well documented by some research groups. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] In comparison with the hydrothermal synthesis method, these new methods have the advantages such as expansion of the chemical compositions, the reduction of the structure directing agent (SDA) concentration, high conversion of the gel, fine particles with high crystallization, etc. Recently, Matsukata and his co-workers have successfully synthesized MWW by DGC method, and compared the morphologies of products synthesized by the DGC and HTS methods.…”

Section: Mcm-22 (Mww) Is a Family Of High Silica Zeolite Which Was Fmentioning

confidence: 99%

Seeding on the Synthesis of MCM-22 (MWW) Zeolite by Dry-Gel Conversion Method and its Catalytic Properties on the Skeleton Isomerization and the Cracking of Hexane

et al. 2005

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The effects of seeding on synthesis of MCM-22 (MWW) have been studied by the dry gel conversion (DGC) method. Highly reproducible crystalline MWW zeolite could be obtained by DGC method, using seeds of calcined sodium MWW with SiO 2 /Al 2 O 3 ¼ 31. Crystallization of MWW phase was completed in the presence of seeds (2 mass% against SiO 2 ) at 150 C within two days. The small amount of seed (0.25 mass% against SiO 2 ) was sufficient for the required phase formation of MWW. The MWW with SiO 2 /Al 2 O 3 ratio from 35 to 66 was obtained as pure phase; however, the crystallinity of MWW decreased with further increase in the ratio: products were contaminated with impurities.The catalytic properties of MWW were examined in the skeleton isomerization and the cracking of hexane, and compared to zeolites such as BEA, MFI, and MOR. The catalytic activities were in the order: MFI>BEA>MWW)MOR; however, the selectivity for the isomerization were in the order: BEA>MWW>MFI. These catalytic properties were due to the differences of structures and acid strength of zeolites.

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Influence of solid-state transformation time on the nucleation and growth of silicalite 1 prepared from layered silicate

Cited by 46 publications

References 11 publications

Zincoaluminophosphate Molecular Sieves with AFI and ATS Topologies: Synthesis by Dry-Gel Conversion Methods and Their Catalytic Properties in the Isopropylation of Biphenyl

Zincoaluminophosphate Molecular Sieves with AFI and ATS Topologies: Synthesis by Dry-Gel Conversion Methods and Their Catalytic Properties in the Isopropylation of Biphenyl

Reactivity and applications of layered silicates and layered double hydroxides

Seeding on the Synthesis of MCM-22 (MWW) Zeolite by Dry-Gel Conversion Method and its Catalytic Properties on the Skeleton Isomerization and the Cracking of Hexane

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