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

In this work, we report a novel integrated inorganic membrane electrode assembly (I(2)MEA) 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 I(2)MEA 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 degrees C. More impressively, using 0.1 M Na2CO3 as the electrolyte, the (IMEAs)-M-2 can continuously electrolyze at 80 mA cm(-2) for 600 hours with a decay rate of as low as 100 mu Vh(-1). This superior stability is attributed to the integrated structure that allows hydroxide ions to transport smoothly. (C) 2014 Elsevier Ltd. All rights reserved.