Ultramicroporous organic materials for selective separation of xenon from krypton

Xenon is found a wide range of applications in our modern life, and its purification and separation is of paramount importance in industry. For this goal, we have synthesized several porous organic frameworks (POFs) from the perspective of pore chemistry. The prepared materials (CTF-0, PAF-45, PAF-67) show almost identical pore size of ~5.0 Å, appreciable surface areas (528.4–1158.5 m2 g−1), substantial micropore volumes (0.158–0.3 cm3 g−1) and high stabilities (400–600 °C). Adsorption measurements demonstrate that the prepared materials have xenon uptakes in the range of 25.2–62.8 cm3 g−1 at 1.0 bar and 298 K, and Henry predictions reveal that they are selective for separating xenon from krypton with selectivities of 5.2–8.1. As a representative material, PAF-45 has been tested for xenon separation by the breakthrough experiment, and selectivity of 12.3 for xenon over krypton and xenon capacity of 92.4 mmol kg−1 are obtained.