Exploring Hydrothermal Synthesis of SAPO-18 under High Hydrostatic Pressure

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

doi:10.3390/nano12030396

Exploring Hydrothermal Synthesis of SAPO-18 under High Hydrostatic Pressure

Nanomaterials (Basel). 2022 Jan 26;12(3):396. doi: 10.3390/nano12030396.

Authors

Affiliations

¹ Institute of Engineering Innovation, The University of Tokyo, Tokyo 113-8656, Japan.
² Department of Chemical System Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
³ Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan.
⁴ Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan.

Abstract

The effect of external hydrostatic pressure on the hydrothermal synthesis of the microporous silicoaluminophosphate SAPO-18 has been explored. The crystallization of the SAPO-18 phase is inhibited at 150 °C under high pressures (200 MPa) when using relatively diluted synthesis mixtures. On the contrary, the use of concentrated synthesis mixtures allowed SAPO-18 to be obtained in all the studied conditions. The obtained solids were characterized with XRD, SEM, ICP-AES, TG and ²⁷Al and ³¹P MAS NMR spectroscopy. The results highlight the importance of the external pressure effect on the hydrothermal synthesis of molecular sieves and its influence on the interaction between the organic molecule and the silicoaluminophosphate network.

Keywords: high pressure; hydrothermal synthesis; non-conventional synthesis; silicoaluminophosphates; water content.

Abstract

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