Morpholinium-Modified, Polyketone-Based Anion Exchange Membranes for Water Electrolysis

Water electrolysis is by far the most appealing method to produce green hydrogen. Among the possible technologies, Anion Exchange Membrane (AEM) water electrolyzers are promising in the medium term, as they make it possible to avoid critical and noble materials as catalyst components. However, AEMs are still lacking in performance and stability, which has become the current research focus. Here, we report the facile and inexpensive chemical modification of polyketone (PK) with a functional unit encompassing morpholinium as the positively charged group, and the fabrication of self-standing membranes. The synthesis products are investigated with an ensemble of physico-chemical and spectroscopic techniques, including solid-state and time-domain NMR, FT-IR, and thermal analysis. The membranes show good Ion Exchange Capacity values in the range 1.48-2.24 mmol g(-1). A preliminary electrolysis test shows that the PK-based membrane has performance comparable to that of a commercial one.

Automated summary

Water electrolysis is the most attractive method for producing green hydrogen, and Anion Exchange Membrane (AEM) water electrolyzers are a promising technology. However, AEMs still need improvement in terms of performance and stability. In this study, we report a simple and cost-effective chemical modification of polyketone (PK) to fabricate self-standing membranes with good ion exchange capacity. Preliminary electrolysis tests show that the PK-based membrane performs similarly to a commercial one.