An Interrupted Zeolite PKU-26 and Its Transformation to a Fully Four-Connected Zeolite PKU-27 upon Calcination
Journal
Chemistry-a European Journal
Journal Volume
25
Journal Issue
13
Pages
3219-3223
Date Issued
2019
Author(s)
Chen, Yanping
Ma, Ning
Huang, Shiliang
Du, Xin
Liao, Fuhui
Zh, Yuexiang
Sun, Junliang
Wang, Yingxia
Abstract
AbstractThe thermal stability and structural transformation mechanism are critical for the industrial applications of zeolites and the design of new framework types. Herein, a new zeolite PKU‐26 has been hydrothermally synthesized under fluoride conditions using a tetraethylammonium (TEA+) cation as the structure‐directing agent (SDA) and its framework contains partial Q3 T atoms [Q3 for T(−O−T)3OH]. Upon calcination, PKU‐26 processed a single‐crystal to single‐crystal transformation to another novel zeolite PKU‐27 with the elimination of terminal −OH groups and enhanced thermal stability up to 650 °C, exhibiting the first Q3→Q4 transformation [Q4 for T(−O−T)4] in 3D zeolite frameworks. The mechanism of the structural transformation, involving proton transfer, framework dehydration, and TO4 reconstruction, is proposed and supported by theoretical calculations.
SDGs
Type
journal article