Novel multi-channel anion exchange membrane based on poly ionic liquid-impregnated cationic metal-organic frameworks

Abstract

The “trade-off” effect between hydroxide conductivity and dimensional stability is challenging issue for anion exchange membrane fuel cells (AEMFCs). In this study, the framework of UiO-66-NH2 is for the first time applied to anion exchange membranes (AEMs). The robust pore walls of UiO-66-NH2 with mechanical and structural durabilities protect the membrane from the excessive swelling effects (a swelling ratio of 7%). In addition, the framework of UiO-66-NH2 is directly modified into (UiO-66-NH2)+Cl− as hydroxide conduction channels by anion stripping for the first time. And we construct well-organized ion nanochannels by the in-situ self-assembly of N,N,N′,N' -tetramethyl-1,6-hexanediamine (TMHDA) and allyl bromide within the highly ordered pores of (UiO-66-NH2)+Cl−. The obtained QA@(UiO-66-NH2)+Cl− then incorporated into pristine membrane (QAPPO) to fabricate the novel multi-channel AEMs. The hydroxide conductivity of QA@(UiO-66-NH2)+Cl−/PPO is up to 123 mS⋅cm−1 at 80 °C, which is greatly improved compared to QAPPO pristine membrane.