Structural analysis of IPC zeolites and related materials using positron annihilation spectroscopy and high-resolution argon adsorption
Year: 2016
Type: article
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.
DOI: 10.1039/c6cp01950a
Institutions: Charles University, Czech Academy of Sciences, Czech Academy of Sciences, Heyrovsky Institute, University of St Andrews, Universidad de Zaragoza, Instituto de Nanociencia y Materiales de Aragón, ETH Zurich, Institute for Chemical and Bioengineering, King Fahd University of Petroleum and Minerals
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2394874851