NiFe2O4 hierarchical nanoparticles as electrocatalyst for anion exchange membrane water electrolysis

A NiFe2O4 catalyst with nanoparticle morphology, obtained by hydrothermal treatment using glucose and urea as precursors, is investigated as an anode catalyst in an anion exchange membrane electrolyser. Structure, morphology and composition are confirmed by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), and X-ray photoelectron spectroscopy (XPS) analyses. The catalyst is sprayed onto one side of the Fumasep® FAA3-50 anion-exchange membrane to produce a catalyst-coated membrane (CCM), which, assembled with a cathode based on a 40% Pt/C catalyst, is investigated in a single-cell configuration with a size of 5 cm2, at a temperature of 30–60 °C. A current density of 2.7 A cm−2 is obtained at 2.2 V and 60 °C, a value more than 25% higher than that recorded with a benchmark IrO2 catalyst at the anode, representing a breakthrough for an anion exchange membrane electrolyser based on FAA3-50 membrane. A time-stability test of 72 h demonstrates the promising durability of this catalyst, which makes it a new reference for future investigations.