Efficient adsorptive separation of acetylene (C2H2) from carbon dioxide (CO2) or ethylene (C2H4) is industrially important but challenging due to the identical dynamic diameter or the trace amount. Here we show an electrostatic potential compatible strategy in a nitroprusside-based Hofmann-type metal-organic framework, Cu(bpy)NP (NP = nitroprusside, bpy = 4,4’-bipyridine), for efficient C2H2 separation. The intruding cyanide and nitrosyl groups in undulating one-dimensional channels induce negative electrostatic potentials for preferential C2H2 recognition instead of open metal sites in traditional Hofmann-type MOFs. As a result, Cu(bpy)NP exhibits a 50/50 C2H2/CO2 selectivity of 47.2, outperforming most rigid MOFs. The dynamic breakthrough experiment demonstrates a 99.9% purity C2H4 productivity of 20.57 mmol g−1 from C2H2/C2H4 (1/99, v/v) gas-mixture. Meanwhile, C2H2 can also be captured and recognized from ternary C2H2/CO2/C2H4 (25/25/50, v/v/v) gas-mixture. Furthermore, computational studies and in-situ infrared spectroscopy reveal that the selective C2H2 binding arises from the compatible pore electro-environment generated by the electron-rich N and O atoms from nitroprusside anions.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Physics and Astronomy(all)