Synthesis Of Porous Materials For The Applications Of Gas Separation And Storage

Porous organic frameworks（POFs）have been a research hotspot because of its high surface area,low framework density and excellent adsorption properties.Owing to the attributes of high surface areas,permanent porosity,tunable pore sizes,diversified structures,functionalization flexibility and excellent stability,POFs have found their widespread applications in energy storage,gas separation,catalysis,photo/electronic devices and biomedical systems,the studies of which have received tremendous attention in recent years.POFs encompassing their family members of covalent organic frameworks（COFs）,polymers of intrinsic microporosity（PIMs）,covalent triazine-based frameworks（CTFs）,conjugated microporous polymers（CMPs）,hyper-crosslinked polymers（HCPs）and porous aromatic frameworks（PAFs）,are evolving as a new class of microporous materials.Xenon has 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 POF materials from the perspective of pore chemistry for capturing xenon.The prepared materials（CTF-0,PAF-45,PAF-67）show almost identical pore size of⁵.0?,appreciable surface areas(528.4-951.4 m² g^-1),substantial micropore volumes(0.158-0.286 cm³ g^-1),and high stability（400-600℃）.Adsorption measurements demonstrate that all materials have large uptakes for xenon(18.6-49.6 cm³ g^-1 at 1.0 bar and 298 K),and IAST predictions reveal that exceptionally high selectivity for xenon over krypton are obtained at 44-57 for Xe/Kr mixtures with the molar ratio of 90/10 at 1.0 bar and 298 K.As a representative material,PAF-45 exhibits a good balance of high selectivity（S=12.4±0.7）and huge capacity(90.3±2.1 mmol kg^-1)for xenon,measured by the breakthrough experiment of simulated nuclear off gas.