Effect of reaction temperature on Fe–Al analcime formation

Katsuki, Kazuko; Suzuki, Hidenori; Hasegawa, Masatoshi; Heike, Michiko; Hosomachi, Noriko; Yamashita, Yuya; Nakamura, Yuta

doi:10.1007/s10934-006-9038-6

Cited by 8 publications

(5 citation statements)

References 19 publications

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“…The solid spheres comprised of amorphous subunits formed in the initial crystallization. During a longer crystallization time, the gel subunits of the sphere started the transition from amorphous to crystalline, and the inception of zeolite crystal nucleus is localized in the shell of the gel particle. − The amorphous subunits in the core region of the sphere are selectively dissolved and crystallized around the crystal nucleus. The hollowing process continued with longer crystallization time until the amorphous subunits completely crystallized, and the well-defined hollow nanovesicles were finally created.…”

Section: Results and Discussionmentioning

confidence: 99%

Hollow Alveolus-Like Nanovesicle Assembly with Metal-Encapsulated Hollow Zeolite Nanocrystals

et al. 2016

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Inspired by the vesicular structure of alveolus which has a porous nanovesicle structure facilitating the transport of oxygen and carbon dioxide, we designed a hollow nanovesicle assembly with metal-encapsulated hollow zeolite that would enhance diffusion of reactants/products and inhibit sintering and leaching of active metals. This zeolitic nanovesicle has been successfully synthesized by a strategy which involves a one-pot hydrothermal synthesis of hollow assembly of metal-containing solid zeolite crystals without a structural template and a selective desilication-recrystallization accompanied by leaching-hydrolysis to convert the metal-containing solid crystals into metal-encapsulated hollow crystals. We demonstrate the strategy in synthesizing a hollow nanovesicle assembly of Fe2O3-encapsulated hollow crystals of ZSM-5 zeolite. This material possesses a microporous (0.4-0.6 nm) wall of hollow crystals and a mesoporous (5-17 nm) shell of nanovesicle with macropores (about 350 nm) in the core. This hierarchical structure enables excellent Fe2O3 dispersion (3-4 nm) and resistance to sintering even at 800 °C; facilitates the transport of reactant/products; and exhibits superior activity and resistance to leaching in phenol degradation. Hollow nanovesicle assembly of Fe-Pt bimetal-encapsulated hollow ZSM-5 crystals was also prepared.

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Section: Results and Discussionmentioning

confidence: 99%

Hollow Alveolus-Like Nanovesicle Assembly with Metal-Encapsulated Hollow Zeolite Nanocrystals

et al. 2016

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“…It was also shown that most of analcime crystals are clean facetted, and some fractures exhibited may be associated with the presence of metallic impurities of Fe and Ti in natrolite syenite. According to previous study [30,31], the additions of Fe and/or Ti into a synthesis mixture in preparation of zeolite led to structural defects in the analcime produced. As the NaOH concentration was higher than 0.5 mol/L, the spherical sodalite with surface covered by short columnar crystals appeared (Figure 4(c) and Figure 4(d)).…”

Section: Effect Of Naoh Concentration Phase Diagram In Namentioning

confidence: 97%

Synthesis of Analcime Crystals and Simultaneous Potassium Extraction from Natrolite Syenite

Chen

Liu

et al. 2017

Advances in Materials Science and Engineering

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Analcime single crystals were successfully synthesized from natrolite syenite powder (K2O 10.89%) and 92.6% of potassium was extracted simultaneously by means of soda roasting followed by alkali-hydrothermal method. Effects of NaOH concentration, reaction temperature, and holding period on the analcime formation and potassium extraction were investigated systemically. The results indicated that NaOH concentration plays an important role in determining the chemical composition of zeolites and size distribution; by turning the NaOH concentrations, three different pure zeolites (i.e., the phillipsite-Na, the analcime, and the sodalite) were prepared. Besides, a higher temperature could accelerate the dissolution of K+ions and enhance the crystallinity degree of zeolite. The reactions involved in the analcime synthesis can be summarized as follows: sodium aluminum silicate dissolution→precipitation and dissolution of metastable zeolite-P→analcime nucleation→analcime growth. The extraction ratio of K+is associated with the types of synthesized zeolites, among which analcime is the most effective to promote potassium leaching out from zeolite lattice position. The optimal condition for analcime crystallization and K+leaching is found to be as follows: 175°C for 4 h in 0.5 mol/L NaOH solution.

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“…Thus, the substitution of other metals for Al 3+ may increase the ion exchange capacity of small pore analcime zeolite. Katsuki et al [8] synthesized pure Fe-Al ANA at 150°C and one week with molar ratio of Fe/(Fe + Al) = 0.1 and 0.2. Also, Kumar et al [9] prepared analcime-C zeolite over the mesoporous clay support followed by deposition of a suitable salt (FeCl 2 ) inside the pores by hydrothermal crystallization.…”

Section: Introductionmentioning

confidence: 99%

Isomorphous Substitution of Iron and Nickel into Analcime Zeolite

Azizi

Yousefpour

2011

Zeitschrift anorg allge chemie

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Studies on the effects of iron and nickel incorporation into the hydrothermal synthesis of ANA zeolite were carried out. The presented work reveals that pure Fe-Al analcime is synthesized by using starting composition with a higher iron(III) content than reported in previous publications. Furthermore, the iron(III) and nickel(II) contents play important roles in the framework of the synthesized zeolite. 759XRD, FT-IR spectroscopy, diffuse reflectance UV/Vis spectroscopy, nitrogen adsorption and SEM were used to characterize the synthesized zeolites. These investigations showed that loading of iron and nickel ions in ANA zeolite changes the pore size and morphology of analcime zeolite.

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Effect of reaction temperature on Fe–Al analcime formation

Cited by 8 publications

References 19 publications

Hollow Alveolus-Like Nanovesicle Assembly with Metal-Encapsulated Hollow Zeolite Nanocrystals

Hollow Alveolus-Like Nanovesicle Assembly with Metal-Encapsulated Hollow Zeolite Nanocrystals

Synthesis of Analcime Crystals and Simultaneous Potassium Extraction from Natrolite Syenite

Isomorphous Substitution of Iron and Nickel into Analcime Zeolite

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