Activated potassium ions as CO2 carriers for PEBAX-5513/KBF4 composite membranes

Abstract

This study showed that potassium tetrafluoroborate (KBF4) could be used as a carrier to facilitate the transport of CO2. A polymer electrolyte membrane was prepared by incorporating KBF4 into poly (ether-block-amide) (PEBAX-5513) with a flexible PE group. The prepared PEBAX-5513/KBF4 electrolyte membrane exhibited CO2 separation performance that was improved by nine times compared to pure PEBAX-5513 and by about seven times compared to a PVP/KF electrolyte membrane. The membrane exhibited a selectivity of 27.9. This improved separation performance increased the transport of CO2 owing to the reversible interaction of the dissociated potassium ions with CO2 molecules. The dissociation of potassium ions upon thermal treatment of the material was confirmed by Fourier transform Raman spectroscopy, and the selective layer in which the separation mechanism was generated was confirmed by scanning electron microscopy.