Polymeric ionic liquids for CO2 capture and separation: potential, progress and challenges

• Main Authors: Zulfiqar, Sonia, Sarwar, Muhammad Ilyas, Mecerreyes, David
• Format: Article
• Language: English
• ISSN: 1759-9954; 1759-9962
• DOI: 10.1039/c5py00842e

The increasing level of carbon dioxide (CO 2 ) in the atmosphere is a big threat to the environment and plays a key role towards global warming and climate change. In this context to combat such issues, polymeric ionic liquids (PILs) serve as potential substitutes that offer an extremely versatile and tunable platform to fabricate a wide variety of sorbents for CO 2 capture, in particular, for flue gas separation (CO 2 /N 2 ) and natural gas purification (CO 2 /CH 4 ). Formerly, there have been several reports on exploitation of ionic liquids for CO 2 sorption with promising results. However, just a few have focused on polymeric ionic liquids which significantly over-performed the sorption efficiency of the molecular ionic liquids. This review is first ever of its kind which showcases the potential of PILs as a new member of the CO 2 adsorbent family. The most dynamic aspect of PILs research at present is the curiosity to explore their potential as solid sorbents for CO 2 capture and separation. This review not only highlights the recent advances in the area of PILs as sorbents for CO 2 uptake but also portrays the forthcoming challenges in improving their efficiency. The effect of various cations, anions, polymer backbones, alkyl substituents, porosity, cross-linking, molecular weight and moisture on the CO 2 sorption capacity and separating efficiency is scrutinized in detail. Moreover, future strategies to increase the CO 2 capture performance of PILs are also discussed. This review presents the potential of polymeric ionic liquids for CO 2 capture whose sorption efficiency surpasses that of molecular ionic liquids.