We have studied the adsorption properties of Xe and Kr in a highly microporous hydrogen-bonded organic framework based on 1,3,5-tris(4-carboxyphenyl)benzene, named HOF-BTB. HOF-BTB can reversibly adsorb both noble gases, and it shows a higher affinity for Xe than Kr. At 1 bar, the adsorption amounts of Xe were 3.37 mmol g-1 and 2.01 mmol g-1 at 273 K and 295 K, respectively. Ideal adsorbed solution theory (IAST) calculation predicts selective separation of Xe over Kr from an equimolar binary Xe/Kr mixture, and breakthrough experiments demonstrate the efficient separation of Xe from the Xe/Kr mixture under a dynamic flow condition. Consecutive breakthrough experiments with simple regeneration treatment at 298 K reveal that HOF-BTB would be an energy-saving adsorbent in an adsorptive separation process, which could be attributed to the relatively low isosteric heat (Qst) of adsorption of Xe. The activated HOF-BTB is very stable in both water and aqueous acidic solutions for more than one month, and it also shows a well-preserved crystallinity and porosity upon water/acid treatment. Besides, HOF-BTB adsorbs about 30.5 wt%, the highest value for HOF materials, of water vapor during the adsorption-desorption cycles, with a 19% decrease in adsorption amounts of water vapor after five cycles.
Bibliographical noteFunding Information:
This work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2019R1I1A1A01062148). This research was also supported by Human Resources Program in Energy Technology of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted nancial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (no. 20174010201640).
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)