Gadolinium doped ceria-impregnated nickel–yttria stabilised zirconia cathode for solid oxide electrolysis cell

Steam electrolysis (H2O → H2 + 0.5O2) was investigated in solid oxide electrolysis cells (SOECs). The electrochemical performance of GDC-impregnated Ni–YSZ and 0.5% wt Rh–GDC-impregnated Ni–YSZ was compared to a composite Ni–YSZ and Ni–GDC electrode using a three-electrode set-up. The electrocatalytic activity in electrolysis mode of the Ni–YSZ electrode was enhanced by GDC impregnation. The Rh–GDC-impregnated Ni–YSZ exhibited significantly improved performance, and the electrode exhibited comparable performance between the SOEC and SOFC modes, close to the performance of the composite Ni–GDC electrode. The performance and durability of a single cell GDC-impregnated Ni–YSZ/YSZ/LSM–YSZ with an H2 electrode support were investigated. The cell performance increased with increasing temperature (700 °C–800 °C) and exhibited comparable performance with variation of the steam-to-hydrogen ratio (50/50 to 90/10). The durability in the electrolysis mode of the Ni–YSZ/YSZ/LSM–YSZ cell was also significantly improved by the GDC impregnation (200 h, 0.1 A/cm2, 800 °C, H2O/H2 = 70/30).