The first example of commensurate adsorption of atomic gas in a MOF and effective separation of xenon from other noble gases

Abstract

In industry, cryogenic rectification for separating xenon from other noble gases such as krypton and argon is an energy and capital intensive process. Here we show that a microporous metal–organic framework, namely Co₃(HCOO)₆ is capable of effective capture and separation of xenon from other noble gases. Henry's constant, isosteric heat of adsorption (Q_st), and IAST selectivity are calculated based on single component sorption isotherms. Having the highest Q_st reported to date, Co₃(HCOO)₆ demonstrates high adsorption capacity for xenon and its IAST selectivity for Xe–Kr is the largest among all MOFs investigated to date. To mimic real world conditions, breakthrough experiments are conducted on Xe–Kr binary mixtures at room temperature and 1 atmosphere. The results are consistent with the calculated data. These findings show that Co₃(HCOO)₆ is a promising candidate for xenon capture and purification. Our gas adsorption measurements and molecular simulation study also reveal that the adsorption of xenon represents the first example of commensurate adsorption of atomic gases near ambient conditions.