Hydrogen Isotope Separation in Metal-Organic Frameworks

In this thesis we present our research on hydrogen isotope separation using metal-organic frameworks (MOFs). Deuterium is one of the two stable isotopes of hydrogen. Despite its wide range of application, currently there is no ideal industrial method that can separate deuterium in a fast and efficient fashion. MOFs are a class of porous materials consisting of metal ions or clusters connected by organic ligands. They have shown great potential in separating hydrogen isotopes via quantum sieving effect. In this thesis, we first provide background on two state-of-art MOFs, Co-MOF-74 and Cu(I)-MFU-4l. Then we elaborate on the statistical theory of selectivity, the mechanism of separation and the basic idea of mass spectrometry, which is the main analytical technique used in this project. We present temperature programmed desorption (TPD) spectra for both samples. Direct separation measurement is made with Co-MOF-74. We confirm that TPD spectra can predict the results of direct separation measurements. The TPD spectra of Cu(I)-MFU-4l predict a selectivity of approximately 6 at easily accessible temperatures (~260K). This shows the practicality of using Cu(I)-MFU-4l for hydrogen isotope separation. Preferential adsorption separation is also performed with Co-MOF-74. The extracted activation energy agrees to within 10% of literature predictions based on quantum zero point energy models