Polyethyleneimine-polyvinylchloride-based crosslinked membranes for use in PEM water electrolysis operating above 100 °C.

Water electrolysis is the most promising method to produce non-fossil fuel derived H 2. The medium temperature (100–350 °C) water (steam) electrolysis is highly promising technology because it can not only reduce energy consumption but also utilize the low-grade waste heat. However, it is challenged by the proton conductive membrane performance. Herein, polyvinyl chloride (PVC) - polyethyleneimine (PEI) hybrid membrane was realized by a simple cross-linking of PVC and PEI. The intercalated nitrogen-containing groups of PEI promote the adsorption and loading rate of phosphoric acid, which offers the proton conductivity for hybrid membrane. The optimized PVC-PEI with content ratio of 1:4 exhibits a maximum proton conductivity of 4.3 × 10−2 S cm−1 at 180 °C and a long-term conductivity stability for 200 h at 140 °C. The PVC-PEI membrane electrode assembly with commercial IrO 2 anode and Pt/C cathode posts high water electrolysis reactivity in the range of 100–180 °C and reliable stability for the water electrolysis at 140 °C. • Proton conductive PVC-PEI membrane was realized by cross-linking of PVC and PEI. • PVC-PEI membrane displays high temperature stability at 100–180 °C. • The intercalated N-containing groups promote the loading rate of H 3 PO 4. • PVC-PEI membrane exhibits a proton conductivity of 4.3 × 10−2 S cm−1 at 180 °C. • PVC-PEI membrane presents a long-term conductivity stability for 200 h at 140 °C. [ABSTRACT FROM AUTHOR]