Poly(vinylpyrrolidone)/KF electrolyte membranes for facilitated CO2 transport

Abstract

In this study, we show for the first time that potassium fluoride (KF) can be utilized as a carrier for facilitated CO₂ transport. A polymer electrolyte membrane was prepared by incorporating KF through coordinate covalent bonding with the amide groups of poly(vinylpyrrolidone) (PVP). The resulting PVP/KF electrolyte membrane showed enhanced CO₂ separation performance compared with neat PVP. The selectivity ratio CO₂/N₂ increased to 4.1 with a CO₂ permeance of 28 GPU. This enhanced separation performance was attributable to the reversible interaction of KF with CO₂ molecules, resulting in the increase of CO₂ transport. The interaction between KF and the amide groups of PVP was confirmed by FT-IR spectroscopy and X-ray photoelectron spectroscopy (XPS). The coordination of potassium ions with the amide groups caused the free ions in KF to be increased, resulting in the favorable interaction with CO₂ molecules.