Quaternized Tröger’s base polymer with crown ether unit for alkaline stable anion exchange membranes

Abstract

Anion exchange membrane fuel cells (AEMFCs) have drawn great attention since the alkaline condition enables the use of non-platinum catalysts. Nevertheless, the lack of alkali-stable and highly conductive anion exchange membranes (AEMs) impedes the development of AEMFCs. Herein, a series of novel quaternized Tröger’s base polymer AEMs are prepared via acid-promoted condensation reaction and Menshutkin reaction. It is found that QTBPCE-2.5 AEM demonstrates the highest hydroxide conductivity of 39.0 mS cm−1 at 30 °C, and this value is higher than that of commercialized Tokuyama AHA. The introduction of intrinsic microporosity into the polymer matrix, which is favorable to the rapid ion conduction, may account for the high conductivity. Furthermore, the loss of ionic exchange capacity and conductivity of QTBPCE-2.5 are both less than 10% after the stability test (1 M KOH, 80 °C, 192 h). The introduction of electron-donating crown ether is responsible for good alkaline stability. The present result shows that the as-designed AEMs have the potential for the applications in AEMFCs.