Performance and stability of nano-structured Pd and Pd0.95M0.05 (M = Mn, Co, Ce, and Gd) infiltrated Y2O3–ZrO2 oxygen electrodes of solid oxide electrolysis cells

• Performance of nano-structured Pd-infiltrated YSZ oxygen electrodes of SOEC is studied.
• Pd-YSZ electrodes are not stable due to significant agglomeration of Pd NPs.
• Co-infiltration of Co, Ce and Gd is effective to inhibit agglomeration of Pd NPs.
• Best performance and stability are obtained on PdCo-YSZ and PdCe-YSZ electrodes.

Nano-structured Pd infiltrated and Pd0.95M0.05 (M = Mn, Co, Ce, and Gd) co-infiltrated Y2O3–ZrO2 (YSZ) electrodes are studied as the oxygen electrodes of solid oxide electrolysis cells (SOECs). The infiltrated Pd-YSZ electrodes show good electrocatalytic activity for the oxygen evolution reaction. For example, the electrode polarization resistance (RE) for 2.0 mg cm−2 Pd infiltrated YSZ is 0.36 Ω cm−2 at 800 °C. RE is not significantly affected by co-infiltrating Pd with Mn and Co, but is enhanced by co-infiltration of Ce and Gd. The co-infiltration of low concentrations of metals in particular Co, Ce and Gd significantly enhances the microstructure and performance stability of the Pd-YSZ electrodes. The results demonstrate that the addition of dopants to the Pd in the form of either an alloy (Co) or a separate phase (Ce and Gd) is beneficial to enhance the performance and stability of Pd based oxygen electrodes of SOECs.