Structural analysis of IPC zeolites and related materials using positron annihilation spectroscopy and high-resolution argon adsorption
| Autor: | Javier Pérez-Ramírez, Arnošt Zukal, M. Navaro, Russell E. Morris, Jacek Jagiello, Sharon Mitchell, Paolo Crivelli, Jiří Čejka, Michael Sterling, Maksym Opanasenko, Pavla Eliášová, Robbie Warringham, Alvaro Mayoral |
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| Přispěvatelé: | University of St Andrews. School of Chemistry, University of St Andrews. EaSTCHEM |
| Rok vydání: | 2016 |
| Předmět: |
NDAS
Analytical chemistry General Physics and Astronomy 02 engineering and technology 010402 general chemistry 01 natural sciences Positron annihilation spectroscopy Adsorption High-resolution absorption QD Physical and Theoretical Chemistry Porosity Chemistry IPC zeolites Sorption Microporous material Pore size distribution QD Chemistry 021001 nanoscience & nanotechnology 0104 chemical sciences Characterization (materials science) Chemical engineering Density functional theory 0210 nano-technology Mesoporous material ADOR |
| Zdroj: | Zaguán. Repositorio Digital de la Universidad de Zaragoza instname |
| ISSN: | 1463-9084 1463-9076 |
| Popis: | 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). 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. Postprint |
| Databáze: | OpenAIRE |
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