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

Abstract

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.

Publisher

American Chemical Society

Publication Date

1-1-2013

Publication Title

Journal of Amercian Chemical Society

Department

Physics and Astronomy

Additional Department

Chemistry and Biochemistry

Document Type

Article

DOI

https://dx.doi.org/10.1021/ja402103u

Notes

Stephen FitzGerald, Physics and Astronomy
Jesse L.C. Rowsell, Chemistry and Biochemistry

Keywords

Iron(II), Coordination sites, Hydrogen adsorption, Isotope-separation, Carbon dioxide, Diffraction, Zeolites, Polymer, Binding design

Language

English

Format

text

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