Fabrication of Redox Tolerant Anode with an Electronic Conductive Oxide of Y-Doped SrTiO3

Abstract

Composite anodes consisting of Ni, Y-doped (YST), and -stabilized (YSZ) were fabricated; the Ni species was impregnated to YST–YSZ powder and then the resulting powder was fired onto the electrolyte at for 5 h in air. The conductive oxide of YST sintered in air showed a conductivity of after reduction in humidified hydrogen (1.2% ) for 100 h and behaved as a metallic conductor with respect to the temperature dependence of conductivity. The influence of the nickel content in the anode of Ni/YST–YSZ on the electrochemical property was studied under 0.6% atmosphere. The cermet of 10 wt % Ni/YST–YSZ showed the minimal polarization resistance among the catalysts with the nickel content in the range of 5–50 wt %. An electrolyte-supported cell employing this anode exhibited a power density of at 0.5 V at despite the extremely low content of Ni. Stable power generation was attained at a constant terminal voltage of 0.7 V in humidified hydrogen (0.6% ) for 21 h. Even after five consecutive redox cycles, the cell performance remained unchanged mainly due to the stable porous framework of YST–YSZ with a low Ni content.