A pi-Conjugated Anion-Exchange Membrane with an Ordered Ion-Conducting Channel via the McMurray Coupling Reaction

The McMurry coupling is a facile, gentle and low-cost chemical reaction for synthesizing. Here, for the first time, we employed the McMurry coupling reaction to prepare pi-conjugated anion exchange membranes (AEMs). The inter-chain pi-pi stacking between adjacent benzene rings induces directional self-assembly aggregation and enables highly ordered ion-conductive channels. The resulting structure was characterized through UV/VIS spectrum, X-ray diffraction (XRD) pattern, small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM) and density functional theory (DFT) calculations, leading to high OH- conductivity of 135.5mScm(-1) at 80 degrees C. Furthermore, the double bonds in the pi-conjugated system also trigger in situ self-crosslinking of the AEMs to enhance dimensional and alkaline stability. Benefiting from this advantage, the as-obtained Cr-QPPV-2.51 AEM exhibits superior alkaline stability (95% conductivity retention after 3000hrs in 1M KOH at 80 degrees C) and high mechanical strength of 34.8MPa. Moreover, the fuel cell using Cr-QPPV-2.51 shows a maximum peak power density of 1.27Wcm(-2) at 80 degrees C.

Automated summary

In this study, pi-conjugated anion exchange membranes (AEMs) were synthesized using the McMurry coupling reaction. The resulting AEMs exhibited high ion conductivity and alkaline stability. These membranes showed promising performance in fuel cell applications.