MOFs are periodic macromolecules composed of metal atoms or metal-containing clusters, also known as secondary building units (SBUs), coordinated to organic ligands/linkers. Their high porosities and the vast design space of SBU/linker pairings make MOFs highly tunable for applications such as gas storage, catalysis, and adsorption-based separations. There have been many studies over the past several years investigating MOFs for ethane/ethylene separations. One of the first examples of a MOF used to purify such mixtures was HKUST-1, which was found to preferentially adsorb ethylene over ethane via complexation between the open metal site in the MOF structure and the p-bond in ethylene. This general observation has since been further supported by numerous studies on other MOFs with open metal sites. However, there are also other mechanisms for imparting olefin-selective adsorption, such as leveraging multiple supramolecular interactions within the MOF pore or molecular sieving. Although MOFs are often designed to be ethylene-selective, ethane-selective MOFs are more useful from a processing perspective as ethane is the minor product in the cracking process that produces ethylene. Finding an appropriate MOF is quite difficult, however, because ethylene is typically more prone to attractive interactions with the adsorbent surface than ethane due to extra electron-density in its π-bond. Still, there are examples of ethane-selective MOFs. Li et al.