Y-doped SrTiO3 based sulfur tolerant anode for solid oxide fuel cells

A solid oxide fuel cell (SOFC) anode with high sulfur tolerance was developed starting from a Y-doped SrTiO3 (SYTO)-yttria stabilized zirconia (YSZ) porous electrode backbone, and infiltrated with nano-sized catalytic ceria and Ru. The size of the infiltrated particles on the SYTO-YSZ pore walls was 30–200 nm, and both infiltrated materials improved the performance of the SYTO-YSZ anode significantly. The infiltrated ceria covered most of the surface of the SYTO-YSZ pore walls, while Ru was dispersed as individual nano-particles. The performance and sulfur tolerance of a cathode supported cell with ceria- and Ru-infiltrated SYTO-YSZ anode was examined in humidified H2 mixed with H2S. The anode showed high sulfur tolerance in 10–40 ppm H2S, and the cell exhibited a constant maximum power density 470 mW cm−2 at 10 ppm H2S, at 1073 K. At an applied current density 0.5 A cm−2, the addition of 10 ppm H2S to the H2 fuel dropped the cell voltage slightly, from 0.79 to 0.78 V, but completely recovered quickly after the H2S was stopped. The ceria- and Ru-infiltrated SYTO-YSZ anode showed much higher sulfur tolerance than conventional Ni-YSZ anodes.