Structural analysis of IPC zeolites and related materials using positron annihilation spectroscopy and high-resolution argon adsorption
Abstract
The advanced investigation of pore networks in isoreticular zeolites and mesoporous materials related to the IPC family was performed using high-resolution argon adsorption experiments coupled with the development of a state-of-the-art non-local density functional theory approach. The optimization of a kernel for model sorption isotherms for materials possessing the same layer structure, differing only in the interlayer connectivity (e.g. oxygen bridges, single- or double-four-ring building units, mesoscale pillars etc.) revealed remarkable differences in their porous systems. Using high-resolution adsorption data, the bimodal pore size distribution consistent with crystallographic data for IPC-6, IPC-7 and UTL samples is shown for the first time. A dynamic assessment by positron annihilation lifetime spectroscopy (PALS) provided complementary insights, simply distinguishing the enhanced accessibility of the pore network in samples incorporating mesoscale pillars and revealing the presence of a certain fraction of micropores undetected by gas sorption. Nonetheless, subtle differences in the pore size could not be discriminated based on the widely-applied Tao-Eldrup model. The combination of both methods can be useful for the advanced characterization of microporous, mesoporous and hierarchical materials.
Citation
Jagiello , J , Sterling , M , Eliášová , P , Opanasenko , M , Zukal , A , Morris , R E , Navaro , M , Mayoral , A , Crivelli , P , Warringham , R , Mitchell , S , Pérez-Ramírez , J & Čejka , J 2016 , ' Structural analysis of IPC zeolites and related materials using positron annihilation spectroscopy and high-resolution argon adsorption ' , Physical Chemistry Chemical Physics , vol. 18 , no. 22 , pp. 15269-15277 . https://doi.org/10.1039/C6CP01950A
Publication
Physical Chemistry Chemical Physics
Status
Peer reviewed
ISSN
1463-9076Type
Journal article
Rights
Copyright 2016, the authors. This work is made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://dx.doi.org/10.1039/C6CP01950A
Description
ETH authors thanks for the grant ETH 33 15-1. PE and JČ acknowledge the financial support from the Czech Science Foundation (P106/12/0189). JPR and JČ gratefully acknowledge the financial support from the European Union Seventh Framework Programme (FP7/ 2007-2013) under grant agreement no. 604307. HRTEM characterization was performed at the Advanced Microscopy Laboratory (LMA) and the research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3).Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.