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A Single‐Molecule Propyne Trap: Highly Efficient Removal of Propyne from Propylene with Anion‐Pillared Ultramicroporous Materials
Author(s) -
Yang Lifeng,
Cui Xili,
Yang Qiwei,
Qian Siheng,
Wu Hui,
Bao Zongbi,
Zhang Zhiguo,
Ren Qilong,
Zhou Wei,
Chen Banglin,
Xing Huabin
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201705374
Subject(s) - propyne , molecule , materials science , microporous material , sorption , crystallography , ion , molecular sieve , selectivity , ion exchange , pyrazine , chemical engineering , chemistry , organic chemistry , catalysis , adsorption , engineering , composite material
Propyne/propylene (C 3 H 4 /C 3 H 6 ) separation is a critical process for the production of polymer‐grade C 3 H 6 . However, optimization of the structure of porous materials for the highly efficient removal of C 3 H 4 from C 3 H 6 remains challenging due to their similar structures and ultralow C 3 H 4 concentration. Here, it is first reported that hybrid ultramicroporous materials with pillared inorganic anions (SiF 6 2− = SIFSIX, NbOF 5 2− = NbOFFIVE) can serve as highly selective C 3 H 4 traps for the removal of trace C 3 H 4 from C 3 H 6 . Especially, it is revealed that the pyrazine‐based ultramicroporous material with square grid structure for which the pore shape and functional site disposition can be varied in 0.1–0.5 Å scale to match both the shape and interacting sites of guest molecule is an interesting single‐molecule trap for C 3 H 4 molecule. The pyrazine‐based single‐molecule trap enables extremely high C 3 H 4 uptake under ultralow concentration (2.65 mmol g −1 at 3000 ppm, one C 3 H 4 per unit cell) and record selectivity over C 3 H 6 at 298 K (>250). The single‐molecule binding mode for C 3 H 4 within ultramicroporous material is validated by X‐ray diffraction experiments and modeling studies. The breakthrough experiments confirm that anion‐pillared ultramicroporous materials set new benchmarks for the removal of ultralow concentration C 3 H 4 (1000 ppm on SIFSIX‐3‐Ni, and 10 000 ppm on SIFSIX‐2‐Cu‐i) from C 3 H 6 .