Non-Isothermal Kinetics of Kr Adsorption by Nanoporous γ-Mg(BH4)2 from in Situ Synchrotron Powder Diffraction
| Autor: | Iurii Dovgaliuk, Yaroslav Filinchuk, Vadim Dyadkin, Dmitry Chernyshov, Mathieu Vander Donckt |
|---|---|
| Přispěvatelé: | UCL - SST/IMCN/MOST - Molecular Chemistry, Materials and Catalysis |
| Rok vydání: | 2020 |
| Předmět: |
crystal structure
Materials science Thermodynamic parameter Kinetics porous frameworks Analytical chemistry Crystal structure 010402 general chemistry Kinetic energy 01 natural sciences One-dimensional channels thermodynamics symbols.namesake Adsorption Mean field theory Molecule Porous materials Synchrotron powder diffraction General Materials Science Nanocrystalline materials Arrhenius equation In-situ synchrotrons 010405 organic chemistry Nanoporous Enzyme kinetics Crystallites Rietveld refinement Non-isothermal kinetic Modified mean fields 0104 chemical sciences adsorption symbols Isobar Atmospheric pressure Diffraction Crystalline phasis |
| Zdroj: | ACS Applied Materials and Interfaces, Vol. 12, no. 6, p. 7710-7716 (2020) |
| ISSN: | 1944-8252 1944-8244 |
| DOI: | 10.1021/acsami.9b19239 |
| Popis: | Crystalline materials with pore dimensions comparable to the kinetic diameters of the guest molecules are attractive for their potential use in adsorption and separation applications. The nanoporous γ-Mg(BH4)2 features one-dimensional channels matching this criterion for Kr uptake, which has been probed using synchrotron powder diffraction at various pressures and temperatures. It results in two coexisting crystalline phases with the limiting composition Mg(BH4)2·0.66Kr expecting the highest Kr content (50.7 wt % in the crystalline phase) reported for porous materials. Quasi-equilibrium isobars built from Rietveld refinements of Kr site occupancies were rationalized with a noncooperative lattice gas model, yielding the values of the thermodynamic parameters. The latter were independently confirmed from Kr fluorescence. We have also parameterized the pronounced kinetic hysteresis with a modified mean-field model adopted for the Arrhenius kinetics. © 2020 American Chemical Society. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|