Highly Effective Hydrogen Isotope Separation in Nanoporous Metal\u2013Organic Frameworks with Open Metal Sites: Direct Measurement and Theoretical Analysis
| Autor: | Thomas Heine, Andreas Mavrandonakis, Hyunchul Oh, Michael Hirscher, Ievgeniia Savchenko |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Air separation
Hydrogen Thermal desorption spectroscopy Nanoporous General Engineering Analytical chemistry General Physics and Astronomy chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 7. Clean energy 01 natural sciences 0104 chemical sciences Isotope separation law.invention Deuterium chemistry law General Materials Science Isotopologue Metal-organic framework 0210 nano-technology |
| Zdroj: | ACS Nano. |
| Popis: | Separating gaseous mixtures that consist of very similar size is one of the critical issues in modern separation technology. Especially, the separation of the isotopes hydrogen and deuterium requires special efforts, even though these isotopes show a very large mass ratio. Conventionally, H/D separation can be realized through cryogenic distillation of the molecular species or the Girdler-sulfide process, which are among the most energy-intensive separation techniques in the chemical industry. However, costs can be significantly reduced by using highly mass-selective nanoporous sorbents. Here, we describe a hydrogen isotope separation strategy exploiting the strongly attractive open metal sites present in nanoporous metal-organic frameworks of the CPO-27 family (also referred to as MOF-74). A theoretical analysis predicts an outstanding hydrogen isotopologue separation at open metal sites due to isotopal effects, which has been directly observed through cryogenic thermal desorption spectroscopy. For H2/D2 separation of an equimolar mixture at 60 K, the selectivity of 12 is the highest value ever measured, and this methodology shows extremely high separation efficiencies even above 77 K. Our theoretical results imply also a high selectivity for HD/H2 separation at similar temperatures, and together with catalytically active sites, we propose a mechanism to produce D2 from HD/H2 mixtures with natural or enriched deuterium content. |
| Databáze: | OpenAIRE |
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