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Title: Capture of heavy hydrogen isotopes in a metal-organic framework with active Cu(I) sites

The production of pure deuterium and the removal of tritium from nuclear waste are the key challenges in separation of light isotopes. Presently, the technological methods are extremely energy- and cost-intensive. Here we report the capture of heavy hydrogen isotopes from hydrogen gas by selective adsorption at Cu(I) sites in a metal-organic framework. At the strongly binding Cu(I) sites (32 kJ mol -1) nuclear quantum effects result in higher adsorption enthalpies of heavier isotopes. The capture mechanism takes place most efficiently at temperatures above 80 K, when an isotope exchange allows the preferential adsorption of heavy isotopologues from the gas phase. Large difference in adsorption enthalpy of 2.5 kJ mol -1 between D 2 and H 2 results in D 2-over-H 2 selectivity of 11 at 100 K, to the best of our knowledge the largest value known to date. Combination of thermal desorption spectroscopy, Raman measurements, inelastic neutron scattering and first principles calculations for H 2/D 2 mixtures allows the prediction of selectivities for tritium-containing isotopologues.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [4] ;  [4] ;  [5] ;  [5] ;  [2] ;  [5] ;  [3] ;  [1] ;  [6]
  1. Max Planck for Intelligent Systems, Stuttgart (Germany)
  2. Jacobs Univ., Bremen (Germany). School of Engineering and Science
  3. Augsburg Univ. (Germany). Inst. of Physics
  4. Max Planck Inst. for Solid State Research, Stuttgart (Germany)
  5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source
  6. Jacobs Univ., Bremen (Germany). School of Engineering and Science; Leipzig Univ. (Germany). Wilhelm-Ostwald-Inst. of Physical and Theoretical Chemistry
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 8; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; nanoporous materials; quantum sieving; hydrogen isotopes separation; inelastic neutron scattering; Raman spectra; unsaturated metal centers; metal-organic frameworks
OSTI Identifier:
1352783