Designable Synthesis of Layered Silicates and Tunable Interlayer Expanded to Zeolites

Small. 2024 Feb 13:e2307323. doi: 10.1002/smll.202307323. Online ahead of print.

Abstract

Layered zeolitic silicates and corresponding interlayer-expanded porous materials exhibit attractive application potential in wide fields. Nonetheless, designable synthesis and structure analysis of layered silicates remain challenging. Herein, two kinds of layered silicates are synthesized using different di-quaternary ammonium-type organic structure-directing agents (OSDAs). Their crystal structures are analyzed and verified by 3D electron diffraction (3D ED) and high-resolution TEM imaging. The suitable configurations of OSDA can lead to desirable interlayer states. Additionally, two new zeolite structures both with 12-membered ring (MR) channels intersected by 8 MR channels and larger interlayer spaces are constructed from layered silicate precursors by interlayer silylation. The new zeolitic material exhibits potential application in adsorption of organic pollution and catalytic reaction. This study is expected to develop versatile ways for the design and synthesis of layered silicates even zeolites and provide references in characterizing layered materials and zeolites as well.

Keywords: interlayer silylation; layered silicate; structure analysis; zeolite.