Synthesis and evaluation of the A-site deficient perovskite La0.65Sr0.3Cr0.85Ni0.15O3-d as fuel electrode for high temperature co-electrolysis enhanced by in situ exsolution of ni nanoparticles
Lanthanum strontium chromite (LSC) perovskite partially doped with 15% of Ni on the B-site as reducible transition metal was investigated with the aim to perform in situ exsolution under reducing conditions. A-site deficient compounds were formulated to enhance the exsolution of the electrocatalyst. Single phase is achieved with the formulation La0.65Sr0.3Cr0.85Ni0.15O3-d (L65SCN) and has been characterized by X-ray diffraction (XRD), Rietveld refinement and scanning electron microscopy (SEM). Exsolution was investigated under reducing conditions in which Ni exsolution was confirmed. Such electrocatalyst was implemented into an electrolyte-supported-cell (ESC) for early electrochemical investigation. Cells were manufactured by screen printing of composite L65SCN/CGO as fuel electrode and La0.58Sr0.4Fe0.8Co0.2O3-d (LSCF) as air electrode on CGO-3YSZ-CGO substrates. These cells were characterized in steam electrolysis at 930°C by Electrochemical Impedance Spectroscopy (EIS). Further microstructural engineering and fine tuning of the manufacturing parameters are essential for a practical use of this electroctalyst for H2O/CO2 co-electrolysis operation.