Highly Selective Quantum Sieving of D2 from H2 by a Metal鈥揙rganic Framework As Determined by Gas Manometry and Infrared Spectroscopy
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- 作者：Stephen A. FitzGerald ; Christopher J. Pierce ; Jesse L. C. Rowsell ; Eric D. Bloch ; Jarad A. Mason
- 刊名：The Journal of the American Chemical Society
- 出版年：2013
- 出版时间：June 26, 2013
- 年：2013
- 卷：135
- 期：25
- 页码：9458-9464
- 全文大小：402K
- 年卷期：v.135,no.25(June 26, 2013)
- ISSN：1520-5126
文摘
The quantum sieving effect between D2 and H2 is examined for a series of metal鈥搊rganic frameworks (MOFs) over the temperature range 77鈥?50 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.