Self-Assembly of Porphyrin to Realize the High Ionic Conductivity of Anion-Exchange Membranes

In recent years, the microphase separation structure of ion-exchange membranes constructed by intermolecular interaction forces, such as hydrogen bond, cation-dipole interaction, and pi-pi interaction, has received extensive attention. Porphyrins can provide an active self-aggregation driving force through pi-pi interaction. Herein, a series of TMAP-Zn-PMHQ-X anion-exchange membranes (AEMs) were rationally designed in which the porphyrin was introduced to construct highly efficient ion channels. The as-prepared membranes are composed of functionalized fluorophobic polymers as the main chain and quaternized zinc porphyrin as the hydrophilic side chain. TMAP-Zn-PMHQ-13.5% with an ion-exchange capacity (IEC) of 0.35 meq.g(-1) has an OH- conductivity of 152.5 mS.cm(-1) and a swelling ratio of 53.3% at 80 degrees C. Meanwhile, the OH- conductivity of the membrane remains 95.76% after being tested in a 2 M NaOH solution at 80 degrees C for 500 h. A single cell based on the TMAP-Zn-PMHQ-13.5% AEM can achieve a power density of 631.6 mW.m(-2) at a current density of 998.9 mA.cm(-2) at 80 degrees C. This kind of porphyrin self-assembled strategy provides an effective way to fabricate AEMs with good OH- conductivity and a relatively low IEC.

Automated summary

In recent years, the microphase separation structure of ion-exchange membranes constructed by intermolecular interaction forces has received extensive attention, with porphyrins providing an active self-aggregation driving force through pi-pi interaction. By introducing porphyrins, a series of highly efficient ion channels have been designed and fabricated, demonstrating good OH- conductivity and relatively low IEC. This porphyrin self-assembled strategy offers an effective way to develop AEMs with desirable properties.