title: 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.
authors.affiliation: Department of Physics and Astronomy, Oberlin College, Oberlin, Ohio 44074, United States. stephen.fitzgerald@oberlin.edu
authors.forename: Stephen A
authors.initials: SA
authors.lastname: FitzGerald
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Pierce
authors.forename: Jesse L C
authors.initials: JL
authors.lastname: Rowsell
authors.forename: Eric D
authors.initials: ED
authors.lastname: Bloch
authors.forename: Jarad A
authors.initials: JA
authors.lastname: Mason
mesh_terms: D003903:Deuterium / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D011789:Quantum Theory; D013696:Temperature
chemical_list: D009942:Organometallic Compounds; D006859:Hydrogen; D003903:Deuterium