Facilitated Transport Membranes With Ionic Liquids for CO Separations.

In recent years, significant development milestones have been reached in the areas of facilitated transport membranes and ionic liquids for CO separations, making the combination of these materials an incredibly promising technology platform for gas treatment processes, such as post-combustion and direct CO capture from air in buildings, submarines, and spacecraft. The developments in facilitated transport membranes involve consistently surpassing the Robeson upper bound for dense polymer membranes, demonstrating a high CO flux across the membrane while maintaining very high selectivity. This mini review focuses on the recent developments of facilitated transport membranes, in particular discussing the challenges and opportunities associated with the incorporation of ionic liquids as fixed and mobile carriers for separations of CO at low partial pressures (<1 atm).