Shell‐like Xenon Nano‐Traps within Angular Anion‐Pillared Layered Porous Materials for Boosting Xe/Kr Separation
Zheng Fang, Lidong Guo, Rundao Chen, Lihang Chen, Zhiguo Zhang, Qiwei Yang, Yiwen Yang, Baogen Su, Qilong Ren, Zongbi Bao
Abstract
Abstract Adsorptive separation of xenon (Xe) and krypton (Kr) is a promising technique but remains a daunting challenge since they are atomic gases without dipole or quadruple moments. Herein we report a strategy for fabricating angular anion‐pillared materials featuring shell‐like Xe nano‐traps, which provide a cooperative effect conferred by the pore confinement and multiple specific interactions. The perfect permanent pore channel (4–5 Å) of Ni(4‐DPDS) 2 MO 4 (M=Cr, Mo, W) can host Xe atoms efficiently even at ultra‐low concentration (400 ppm Xe), showing the second‐highest selectivity of 30.2 in Ni(4‐DPDS) 2 WO 4 and excellent Xe adsorption capacity in Ni(4‐DPDS) 2 CrO 4 (15.0 mmol kg −1 ). Crystallography studies and DFT‐D calculations revealed the energy favorable binding sites and angular anions enable the synergism between optimal pore size and polar porosity for boosting Xe affinity. Dynamic breakthrough experiments demonstrated three MOFs as efficient adsorbents for Xe/Kr separation.