Remarkable separation of C5 olefins in anion-pillared hybrid porous materials

Abstract

C5 olefin separation is of great importance and challenge in industry with the increasing demand for synthetic rubber. However, the related study is limited due to the complex compositions and the similar boiling points. Here, we for the first time employ two anion-pillared hybrid porous materials (ZU-62 and TIFSIX-2-Cu-i) towards the challenging separation of C5 olefin mixtures (trans-2-pentene, 1-pentene and isoprene). These two adsorbents not only exhibit the unprecedented separation performance, but also show excellent recycle performance. Owing to the favorable electrostatic environment within a suitable confined space, TIFSIX-2-Cu-i is able to distinguish the three C5 olefins (trans-2-pentene, 1-pentene and isoprene) with a high uptake of trans-2-pentene (3.1 mmol·g-1). ZU-62 (also termed as NbOFFIVE-2-Cu-i) with contracted aperture size shows exclusion effect to the relatively large molecule of isoprene at low pressure range (0–6 kPa), contributing to the excellent separation selectivity of 1-pentene/isoprene (300). The excellent separation performance of ZU-62 and TIFSIX-2-Cu-i is verified by the breakthrough experiment. And interestingly, the regeneration tests show that C5 olefins can be easily desorbed from ZU-62, TIFSIX-2-Cu-i under 298 K. Moreover, the detailed adsorption behavior is further revealed by simulation studies.