Highly Selective Quantum Sieving of D2 from H2 by a Metal–Organic Framework As Determined by Gas Manometry and Infrared Spectroscopy

The quantum sieving effect between D2 and H2 is examined for a series of metal–organic frameworks (MOFs) over the temperature range 77–150 K. Isothermal adsorption measurements demonstrate a consistently larger isosteric heat of adsorption for D2 vs H2, with the largest difference being 1.4 kJ/mol i...

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Bibliographic Details
Published in:Journal of the American Chemical Society 2013-06, Vol.135 (25), p.9458-9464
Main Authors: FitzGerald, Stephen A, Pierce, Christopher J, Rowsell, Jesse L. C, Bloch, Eric D, Mason, Jarad A
Format: Article
Language:English
Subjects:
Deuterium - chemistry
Hydrogen - chemistry
Organometallic Compounds - chemistry
Quantum Theory
Temperature
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Summary:The quantum sieving effect between D2 and H2 is examined for a series of metal–organic frameworks (MOFs) over the temperature range 77–150 K. Isothermal adsorption measurements demonstrate a consistently larger isosteric heat of adsorption for D2 vs H2, with the largest difference being 1.4 kJ/mol in the case of Ni-MOF-74. This leads to a low-pressure selectivity for this material that increases from 1.5 at 150 K to 5.0 at 77 K. Idealized adsorption solution theory indicates that the selectivity decreases with increasing pressure, but remains well above unity at ambient pressure. Infrared measurements on different MOF materials show a strong correlation between selectivity and the frequency of the adsorbed H2 translational band. This confirms that the separation is predominantly due to the difference in the zero-point energies of the adsorbed isotopologues.
ISSN:0002-7863
1520-5126
DOI:10.1021/ja402103u