Exploring Hydrothermal Synthesis of SAPO-18 under High Hydrostatic Pressure

Simancas, Raquel; Takemura, Masamori; Yonezawa, Yasuo; Sukenaga, Sohei; Ando, Mariko; Shibata, Hiroyuki; Anand, Chokkalingam; Iyoki, Kenta; Okubo, Tatsuya; Wakihara, Toru

doi:10.3390/nano12030396

Cited by 7 publications

(2 citation statements)

References 39 publications

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“…Zeolitic materials, an important class of crystalline microporous solids with uniform pores and cavities, have emerged as a versatile platform for such industrial applications as catalysis, adsorption, separation, and energy storage. − Typically, these materials are synthesized under solvent-mediated conditions in sealed autoclaves, such as hydrothermal − and solvothermal − syntheses, which show some intrinsic shortcomings, such as high autogenous pressures, long crystallization times, low product yields, and waste liquid discharges . Alternatively, dry-gel conversion − and solvent-free synthesis − can alleviate these drawbacks in some extent.…”

Section: Introductionmentioning

confidence: 99%

Solid-State Synthesis of Aluminophosphate Zeotypes by Calcination of Amorphous Precursors

Tao

Wang

et al. 2023

J. Am. Chem. Soc.

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Because of the growing interest in the applications of zeolitic materials and the various challenges associated with traditional synthesis methods, the development of novel synthesis approaches remains of fundamental importance. Herein, we report a general route for the synthesis of aluminophosphate (AlPO) zeotypes by simple calcination of amorphous precursors at moderate temperatures (250–450 °C) for short reaction times (3–60 min). Accordingly, highly crystalline AlPO zeotypes with various topologies of AST, SOD, LTA, AEL, AFI, and -CLO, ranging from ultra-small to extra-large pores, have been successfully synthesized. Multinuclear multidimensional solid-state NMR techniques combined with complementary operando mass spectrometry (MS), powder X-ray diffraction, high-resolution transmission electron microscopy, and Raman characterizations reveal that covalently bonded fluoride in the intermediates catalyze the bond breaking and remaking processes. The confined organic structure-directing agents with high thermal stability direct the ordered rearrangement. This novel synthesis strategy not only shows excellent synthesis efficiency in terms of a simple synthesis procedure, a fast crystallization rate, and a high product yield, but also sheds new light on the crystallization mechanism of zeolitic materials.

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Section: Introductionmentioning

confidence: 99%

Solid-State Synthesis of Aluminophosphate Zeotypes by Calcination of Amorphous Precursors

Tao

Wang

et al. 2023

J. Am. Chem. Soc.

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“…Moreover, this approach enables the manipulation of product morphology, size, and structure, thereby influencing the catalytic activity of NiCo 2 O 4 . The hydrothermal synthesis method can also be utilized for synthesizing various oxides, such as ZnMoO 4 [20], NiMoO 4 [21], Sn 3 O 4 [22], and SAPO-18 [23], and can be applied in specific catalytic processes.…”

Section: Introductionmentioning

confidence: 99%

Application of a Response Surface Method for the Optimization of the Hydrothermal Synthesis of Magnetic NiCo2O4 Desulfurization Catalytic Powders

Zhang

Shang

et al. 2023

Catalysts

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In this study, nickel cobaltate (NiCo2O4) powders are employed as a catalyst in conjunction with persulfate for the development of a catalytic oxidation system to enhance fuel desulfurization. The hydrothermal synthesis conditions of NiCo2O4 powders, which significantly influenced the desulfurization efficiency, were optimized using a response surface methodology with a Box–Behnken design. These conditions were ranked in the following order: calcination temperature > hydrothermal temperature > calcination time > hydrothermal time. Through the optimization process, the ideal preparation conditions were determined as follows: a hydrothermal temperature of 143 °C, hydrothermal time of 6.1 h, calcination temperature of 330 °C, and calcination time of 3.7 h. Under these optimized conditions, the predicted desulfurization rate was approximately 85.8%. The experimental results closely matched the prediction, yielding a desulfurization rate of around 84%, with a minimal error of only 2.1%. To characterize the NiCo2O4 powders prepared under the optimal conditions, XRD, SEM, and TEM analyses were conducted. The analysis revealed that the microscopic morphology of NiCo2O4 exhibited a rectangular sheet structure, with an average particle size of 20 nm. Additionally, fan-shaped NiCo2O4 particles were observed as a result of linear and bundle agglomerations. Thus, this work is innovative in its ability to synthesize nano-catalysts using hydrothermal synthesis in a controllable manner and establishing a correlation between the hydrothermal synthesis conditions and catalytic activity.

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