LAUSR

The study deals with the modification of commercial Ni/GDC powder with iron and its use as fuel functional electrode for Solid Oxide H2O electrolysis. The Fe‐NiO/GDC samples were prepared with the Deposition‐Precipitation method and characterized, in their oxidized and reduced form, by using BET, HR‐TEM, SAED, XRD, XPS and TG analysis in the presence of H2O. The electrochemical investigation deals with the comparison of single SOECs at 900°C, under various pH2O/pH2 ratios. In the oxidized powders iron was detected, both in the bulk and on the surface, in the form of crystallized Fe2O3 species, which during H2‐reduction interacted with NiO towards the formation of a Ni‐Fe alloy. The latter promoted the electrochemical performance of the Fe‐Ni/GDC electrodes, where there are indications of strong dependence on the Fe wt% content. Specifically, the performance of the cell with 0.5 wt% Fe‐Ni/GDC was threefold higher than that with Ni/GDC. On the other hand, the cell with 2 wt% Fe‐Ni/GDC was worse, implying that the promoting effect of Fe lies on quite low wt% content. Finally, the examined Fe‐doped electrodes exhibited increase of polarization in high pH2O. This is primarily ascribed to the fact that Fe‐Ni/GDC electrodes seem more susceptible to H2O oxidation. Overall, Fe is considered as a promising Ni/GDC dopant, capable to substitute noble metals like Au, but further investigation is required for the elucidation of key preparation and performance parameters.