Xenon Regeneration by CO₂ Removal from Exhaled Anesthetic Gas Mixture by a Hybrid Ultramicroporous Material with Customized Nanotrap

Xenon, Xe, is a noble gas that is present in the atmosphere in trace amounts. Nevertheless, despite its low abundance and relatively high cost, Xe has utility, including as an anesthetic and a neuroprotectant in the medical industry. Xe recycling after usage will represent an approach that shall enable more widespread adoption in medicine. In this work, it is reported that the microporous metal-organic framework (MOF) material NKU-1017(Si) can enable Xe recycling by capturing CO₂ impurities from exhaled anesthetic Xe gas mixtures at ambient temperature for facile and efficient recycling of Xe. The performance of NKU-1017(Si) is driven by its ultramicroporous structure that offers a high density of aromatic rings on the pore surface along with other functionality to form a bespoke nanotrap for CO₂ with multiple C─H^…π interaction sites that result in CO₂/Xe selectivity of 15.5 at ambient conditions. Whereas NKU-1017(Si) adsorbs both H₂O (300 cm³g⁻¹) and CO₂ (70 cm³g⁻¹), humidity does not affect dynamic breakthrough performance. Theoretical studies provide insight into the CO₂-framework binding interactions that drive this performance. The superior separation selectivity of NKU-1017(Si) under ambient conditions enables a new approach for the Xe recovery through the regeneration of anesthetic gas for more widespread application in medicine.