Structure and 3D-3D Topotactic Transformation of the Aluminophosphate Molecular Sieve PST-5 and Its Implication in New Zeolite Structure Generation

15 June 2020, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

Zeolites have attracted great interest over recent decades. Their unique pore structures of molecular dimensions and tunable compositions make them ideal for shape selective catalysis and separation. However, targeted synthesis of zeolites with new pore structures and compositions remains a key challenge. Here, we propose a novel approach based on a unique 3D-3D topotactic transformation, which takes advantage of weak bonding in zeolites. This is inspired by the structure transformation of PST-5, a new aluminophosphate molecular sieve, to PST-6 by calcination at 500 °C. The structure of PST-5 was determined from micrometer-sized crystals by 3D electron diffraction (3DED, also known as MicroED). We found that the 3D-3D topotactic transformation involves two types of building units where penta- or hexa-coordinated Al is present. We applied this approach to several other zeolite systems and predicted a series of new zeolite structures that would be synthetically feasible. This method provides a new concept for the synthesis of targeted zeolites, especially those which may not be feasible by conventional methods.

Keywords

Zeolites
Aluminophosphates
Topotactic transformation
3D electron diffraction
Electromicroscopy
MicroED

Supplementary materials

Title
Description
Actions
Title
Huang et al
Description
Actions

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.