An Ultramicroporous Hydrogen-Bonded Organic Framework Exhibiting High C2H2/CO2 Separation

The separation of C2H2/CO2 is not only industrially important for acetylene purification but also great scientific challenge due to their very similar molecular size and physical properties. To address this difficulty, herein, we present an ultramicroporous hydrogen-bonded organic framework (HOF-FJU-1) from tetracyano bicarbazole to separate C2H2 from CO2 by taking advantage of differences in their electrostatic potential distribution. This material possesses a suitable pore environment and electrostatic potential distribution fitting well to C2H2, thus showing extra strong affinity to C2H2 (46.73 kJ mol(-1)) and the highest IAST selectivity of 6675 for C2H2/CO2 separation among the adsorbents reported. The single crystal X-ray diffraction reveals that the suitable pore environment in HOF-FJU-1 provides multiple C-H center dot center dot center dot pi and hydrogen-bonded interactions N center dot center dot center dot H-C with C2H2 molecules. Dynamic breakthrough experiments demonstrate its outstanding separation performance to C2H2/CO2 mixtures.

Automated summary

In this study, an ultramicroporous hydrogen-bonded organic framework material was developed for efficient separation of C2H2 from CO2, showing strong affinity and high selectivity.