Integrated inorganic membrane electrode assembly with layered double hydroxides as ionic conductors for anion exchange membrane water electrolysis

•A novel integrated inorganic membrane electrode assembly (I2MEA) is fabricated.•The integrated structure allows hydroxide ions to transport smoothly.•The I2MEA is applied to anion exchange membrane water electrolysis.•The I2MEA exhibits a promising performance and durability for hydrogen generation.

In this work, we report a novel integrated inorganic membrane electrode assembly (I2MEA) for anion exchange membrane (AEM) water electrolysis by using inorganic Mg-Al layered double hydroxides (Mg-Al LDHs) as an ionic conductor. Mg-Al LDHs synthesized by a two-step approach exhibit high hydroxide ion conductivity and superior stability. The resultant ionic conducting nanoparticles are cold-pressed to form a membrane and mixed with a non-precious electrocatalyst to form the catalyst layer onto each side of the membrane. As such, an I2MEA is formed and used in a water electrolysis setup. It is shown that the present water electrolysis results in a maximum current density of 208 mA cm−2 with 0.1 M NaOH as the electrolyte and a cutoff voltage of 2.2 V at 70 °C. More impressively, using 0.1 M Na2CO3 as the electrolyte, the I2MEAs can continuously electrolyze at 80 mA cm−2 for 600 hours with a decay rate of as low as 100 μV h−1. This superior stability is attributed to the integrated structure that allows hydroxide ions to transport smoothly.

Graphical abstractIntegrated inorganic membrane electrode assemblies (I2MEAs) are fabricated with non-precious electrocatalysts and Mg-Al layered double hydroxides as the hydroxide ion conductors. The I2MEAs fabrication is a simple preparation approach with a promising electrocatalytic activity and stability toward hydrogen generation.Figure optionsDownload full-size imageDownload as PowerPoint slide