In order to maximize the stability and efficiency of anion exchange membrane water electrolysis (AEMWE) under alkaline conditions, anion exchange functional groups should be bonded to a polymer backbone as much as possible to maintain mechanical strength and minimize the nuclear substitution/Hoffmann reactions. Commercially available anion exchange membranes were analyzed for thickness, electrical resistance, conductivity, ion exchange capacity (IEC), water uptake (WU), swelling ratio (SR) and surface images under alkaline conditions (Figure 1). Although several membranes (Astom's ASE/AHA and Selemion's AHO membranes: within 15% of the IEC value) appear to be very stable under alkaline conditions, strong swelling and softening problems caused by high water temperatures need to be resolved. Graphene oxide, a carbon-based porous nanomaterial modified from graphite, was manufactured to minimize swelling and softening during the AEMWE operation. As a result of various characterizations (Bio-TEM, FTIR, XPS, Raman spectroscopy and XRD) of the produced graphene oxide (Figure 2), it has a sheet structure that cannot be identified in graphite, and contains hydroxyl, carboxyl, epoxy, alkoxy, and ether functional groups. It is believed that the stability and efficiency of AEMWE can be secured by using the porous nanomaterial prepared in this study for cross-linking of anion exchange membrane.

Figure 1. Characterization of commercially available anion exchange membranes under alkaline conditions

Figure 2. Preparation of modified graphene oxide and comparison of characterizations

Kyoung Hoon Chu

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