Electrochemical Pumping Behavior of an Anion Exchange Membrane CO_2 Separation Device

摘要

Anion exchange membranes (AEM) are well studied in the context of fuel cells and water electrolyzers, as they permit the use of non-noble catalysts. However, such alkaline systems have a notable drawback of carbonation when they are operated using atmospheric air, which is known to reduce the anion conductivity of the membrane. The (bi)-carbonate ions are removed from the membrane through the migration of hydroxide ions, also known as the self-purging mechanism. This carbonation effect of AEMs can be utilized to selectively remove CO_2 from a dilute gas mixture (e.g., flue gas or air) and transport it across the membrane, as shown in Figure 1.