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.

Integrated 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 as PowerPoint slide