Structural analysis of IPC zeolites and related materials using positron annihilation spectroscopy and high-resolution argon adsorption

0461874 - ÚFCH JH 2017 RIV GB eng J - Journal Article
Jagiello, J. - Sterling, N.C. - Eliášová, Pavla - Opanasenko, Maksym - Zukal, Arnošt - Morris, R. E. - Navaro, M. - Mayoral, A. - Crivelli, P. - Warringham, R. - Mitchell, S. - Pérez-Ramirez, J. - Čejka, Jiří
Structural analysis of IPC zeolites and related materials using positron annihilation spectroscopy and high-resolution argon adsorption.
Physical Chemistry Chemical Physics. Roč. 18, MAY 2016 (2016), s. 15269-15277. ISSN 1463-9076. E-ISSN 1463-9084
R&D Projects: GA ČR(CZ) GAP106/12/0189
EU Projects: European Commission(XE) 604307 - CASCATBEL
Institutional support: RVO:61388955
Keywords : PORE-SIZE * POROUS MATERIALS * LIFETIME SPECTROSCOPY
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 4.123, year: 2016

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.
Permanent Link: http://hdl.handle.net/11104/0261437