Uptake and separation of Xe and Kr by a zeolitic imidazolate framework with a desirable pore window

Crystalline solids of zeolitic imidazolate framework (ZIF)-69 with a suitable pore window size matching with atomic diameter of xenon is utilized for this task, showing notable performance for Xe/Kr capture and separation as well as decent hydrolytic and irradiation stabilities. The results illustrate that the saturated uptake amount of Xe by ZIF-69 is 2.46 mmol/g at 298 K, while Kr uptake is only 0.55 mmol/g. Importantly, the separation ratio of Xe/Kr is 8.35, one of the highest values among all solid sorbent material reported up to now. These findings suggest that ZIF-69 is a potential candidate for the application of xenon capture and purification form a gas mixture containing Kr.